The document discusses the evolution of human motivation and emotion from a scientific perspective. It outlines how early theories like animism were subjective and lacked evidence, while the scientific method using empirical observation, operational definitions, and experimentation allows for more objective study. Key developments included Darwin suggesting studying body language objectively, and paradigms shifting from introspection to examining behaviors across species, cultures, and brain physiology to understand evolutionary influences on our motivations of survival, reproduction, and dealing with conflict.

1. Part 1: History and Overview
 human ancestors possessed basic human emotions, instincts, and behavioral drives
o most mammals have these things
o but they DON'T have language, which sets us apart from our ancestors more than
anything else
 humans can think about and directly communicate their feelings, whereas our ancestors could
only express their emotions through body-language
o this is good, because we can more easily categorize and understand our emotions
o this is also bad, because language, unlike body-language, is subjective; my
understanding of "happy" is not the same as someone else's
o as a result, it is hard to objectively study emotions
 today's lesson:
o animism
o mythology
o other things misattributed as causes of behavior
o subjective/inadequate data
 animism: attributing spirits to the behavior of humans and animals, possibly also plants, natural
forces, abstract concepts, and faraway things
o humans have "souls," and our souls control our bodies
o strange behavior comes from spiritual possession
 "spirited" "dispirited" "in good spirits" "drinking spirits"
o no scientific evidence for this
 feelings are sometimes falsely attributed to organs
o the heart doesn't actually have anything to do with love or sadness
o the stomach has nothing to do with bravery
 religion has made many statements about motivation and emotion, few of which can be backed
up by hard evidence
o religion is treated as an authority by many people, and those people don't always
question authority
 introspection: thinking about your own thoughts, how they come about, and what they mean
o many philosophers came up with ideas about emotion and motivation through
introspection
 Descartes invented dualism, the idea that the mind and body are two different entities
o your mind is your soul, your consciousness, and it controls the body
o the mind and the body cannot be reduced to the same thing
o the body is responsible for desire and motivation, but the mind is responsible for
emotion
o Descartes believed that the Pineal gland (the gland at the center of the brain) was the
interface between the mind and body
 this is partially right; the Pineal gland may be responsible for our mood
 Hobbes believed in hedonism, the idea that humans are inherently barbaric and simple
o all humans instinctively seek pleasure and avoid pain
o we cannot learn to betray our instincts; all human behavior is rooted to these desires
 Locke believed in the tabula rasa, the idea that the human mind starts off as a blank slate
o all thought and behavior comes from our experiences
~~~~~~~~~~~~

2.  today's lesson:
o the scientific method
o objective ways to study emotion and motivation
o discard preconceptions and build new ideas through systematic, empirical observation
 empiricism: using data from direct observation, not subjective experience
o introspection is not empirical, because you cannot objectively observe your own
emotions
o due to the limitations of language, you cannot explain your findings in a way other
people will understand completely
o if only there was some way to measure and explain your findings without room for
misinterpretation… hmm...
 operational definition: a definition that leaves no room for subjectivity or misinterpretation
o explains a concept in concrete, empirically measurable terms
 for example, an operational definition of anxiety might include sweating,
nausea, fast heartbeat, etc.
o scientists need operational definitions to replicate other scientists' experiments
 if you don't have an operational definition of the concept measured in another
scientist's experiment, how do you know you're both measuring the same
thing?
o at last, the problem of language is solved! scientists can now be objective about
emotion and motivation!
 operational definitions aren't enough; for true objectivity, you need to follow the scientific
method
o the scientific method relies on experiments that measure concepts with strict, easy-to-
understand operational definitions
o some scientists perform statistical analyses
o when the experiment is over, scientists attempt to publish their findings
o before the results can be published, they must undergo rigorous skeptical evaluation
from other scientists
 these scientists will point out flaws in your research
 they will also give you an idea of what to research next ("what DOESN'T this
study tell us?")
 NO UNQUESTIONED AUTHORITIES! if someone tells you you're wrong, you have
to take their opinions into consideration
o after the study gets published (IF it gets published), other scientists will replicate the
experiment
 if the new experiment gets similar results, your findings are correct! if not, your
findings may be discarded
 Thomas Kuhn came up with the idea of the paradigm shift: when someone discovers something
new (this could be a new technology, a new scientific principle, etc.), it triggers a revolution that
forces scientists to reconsider their worldview
o the video, "A Visual Metaphor for Paradigm Shifts," explains this concept in detail:
 the scientific world is a collection of facts
 scientists sometimes add new facts to this collection
 many scientific "facts" depend on the validity of certain theories, and these
theories exist within a paradigm
 if a scientific observation does not fit prevailing theories, scientists must edit or
discard those theories to account for the new observation

3.  if a new theory comes along that can explain the new observation, along with
every existing scientific fact, that theory goes on to shape a new paradigm in the
scientific world
 this is called a paradigm shift
o here's a real-world example of a paradigm shift
 Darwin explained evolution through a process called pangenesis
 lots of people accepted Darwin's explanation, because there were no
other theories at the time, nor was there any contradictory data
 but when Mendel did find contradictory data, he proposed the theory of
Mendelian inheritance, and Darwin's pangenesis was discarded
 Mendel, unlike Darwin, performed experiments before coming up with
theories
 it was Darwin who first suggested that we study emotions not through introspection, but
through empirical observation
o he believed we should study body language, because unlike our own emotions, body
language can be observed with objectivity
 when studying emotion and motivation from a genetic perspective, we should use these
methods:
o cross-species comparison: if multiple species react to a stimulus in the same way, those
species might be genetically related
o examination of expressions through development: if a certain behavior is present all
through an organism's development, that behavior might be innate and therefore
rooted in genes
o examination of expressions across human cultures: if people from all over the world
exhibit the same behavior, that behavior is probably universal; genes could be involved
o study of special populations: special populations are unaffected by the progression of
technology and society; if people from these populations exhibit a certain behavior, that
behavior could be innate
 James argued that we must abandon old philosophies and preconceptions, and instead use the
scientific method to study ourselves
o he believed that humans had a richer variety of emotions than any other animal
 Watson, like Locke, believed in the tabula rasa; he thought that all behaviors were learned
o "Give me a dozen healthy infants…" and I can raise them to do anything, regardless of
their race, gender, or cultural heritage
o he was a behaviorist
 Skinner was also a behaviorist; he believed that instinct was a myth
o he invented the Skinner box experiment
 put a small animal in a box with two buttons; one button drops a food pellet,
the other delivers an electric shock
 the animal will eventually learn to only push the food button, demonstrating a
learned behavior
 modern psychology, including the study of motivation and emotion, has been greatly influenced
by biology
o evolutionary biology helps psychologists understand why we exhibit certain behaviors
o physiology tells us where our behaviors come from (what part of the brain causes
happiness?)
o other modern influences: experimental psychology, biopsychology, evolutionary
psychology, animal behavior, neuroscience and neuroendocrinology

4.  the basic dimensions of motivation and emotion are best understood through natural selection
Part 2: The Evolution of Motivation and Emotion
 our three basic motivations:
o survival
o reproduction
o conflict
 motivations related to survival:
o thirst
 the feeling of "thirst" is regulated by our endocrine system
 when you get really thirsty, water is all you can think about
 when you get really, REALLY thirsty, you might become confused or start
hallucinating
 most people in North America never get this thirsty
o hunger
 hunger, like thirst, is regulated by our endocrine system
 and again, like thirst, most people in North America never get so hungry as to
consume their thoughts
o elimination
 unlike most animals, humans can have trouble with elimination
 we need to eliminate waste in specific places, like bathrooms; if we eliminate
anywhere else, it's embarrassing
 if you are physically unable to pass waste, it can be very distressing
o temperature regulation
 humans sweat when they get too hot; other animals have different methods of
regulating their temperature
 but no matter what we do to cool down or heat up, the drive itself is the same
o pain and escape behavior
 humans usually try to escape things that cause them pain (duh)
 painful things are generally bad for you; people who can't feel pain often hurt
themselves
o fear and avoidance
 as with pain, things that cause a fear response are usually bad for you
 however, there are lots of things we should be afraid of but aren't (cars, guns,
etc.); see evolutionary lag
 motivations related to reproduction
o (after all, what's the point of survival if you can't pass on your genes?)
o courtship
 you have to attract a mate before you can have sex with them
o sexual behavior
 if you don't have sex properly, you can't reproduce, and your genes don't get
passed down (again, duh)
o pregnancy, nursing, and nurturance of offspring
 some animals are driven to give birth under specific conditions; otherwise, their
offspring won't survive
 offspring may need parental guidance, depending on their species

5.  if human babies don’t have parents to look after them, they die
 nursing is also important; the benefits provided by milk are tremendous
o favoring kin
 by favoring kin, you improve your inclusive fitness (defined below)
 your kin shares your genes, so if you help them reproduce, you are effectively
passing down a portion of your genes
 motivations related to conflict
o threat and aggression
 if you threaten other members of your species, they will know not to mess with
you
 ...unless they're clearly stronger than you, in which case the "fear and
avoidance" motivation may take priority
o territoriality and dominance
 by securing territory, you also secure resources and a living space
 if you don't establish your place in the social hierarchy, other animals will mess
with your territory
 so basically: survive until you reproduce, reproduce successfully, and make sure your offspring
can survive until they reproduce, all while protecting your resources
 all of these motivations apply to humans, whether we are aware of them or not
o in 2013, Swami et al. conducted this study:
 recruited 120 male subjects
 placed the subjects in two conditions, 60 per condition
 the first condition consisted of hungry men
 the second condition consisted of men who had just finished eating
 sample populations: people who were about to enter/exit the cafeteria
 had subjects complete a survey to make sure they really were
hungry/full
 showed subjects an array of 3D models
 the models looked like blonde women wearing bikinis
 the only difference between each model was breast size; some models
had big breasts, others had smaller breasts
 experimenters used 3D models instead of real women, because real
women have physical differences besides breast size, and those
differences are hard to account for
 asked subjects to rate the models based on their attractiveness
 subjects in the hungry condition preferred big-breasted women
 why?
 big-breasted women have more body fat, and people high in body fat
tend to have better access to food
 if a man courts a big-breasted woman, he might get a meal out of it
 just to reiterate, this is not a conscious decision on the man's part
 so, yes, humans do possess subconscious motivations
 all motivations exist to help us pass down our genes
o individual selection: a gene that helps its owner survive is likely to get passed down
 survive to reproduce, reproduce to pass down genes, etc.
 a gene that doesn't help its owner survive is less likely to get passed down
 a gene that impedes its owner's survival is unlikely to get passed down, unless
that gene contributes to sexual selection (see below)

6. o kin selection: a gene that encourages you to help your kin is likely to get passed down,
because your kin shares your genes
 if your kin reproduce, some of your genes get passed down
 this may include the genes that encourage you to help your kin
 in this way, your genes are indirectly replicating themselves
 nepotism: the tendency to favor relatives over others, caused by kin selection
 to make things perfectly clear, kin selection produces nepotism; they
aren't the same thing
 how do you maximize both individual and kin selection?
o according to the principles of individual selection, if a gene impedes your survival, it
shouldn't get passed down
o ...unless your kin also have that gene, and it promotes nepotism
o so when does individual selection take precedence over kin selection?
 Hamilton's rule: if the cost of helping kin outweighs the reproductive benefits
of nepotism, the nepotism-promoting gene will not get passed down
 nepotism has to result in a net gain of reproductive fitness
 basically, r*B>C, where B=reproductive benefit, C=reproductive cost,
and r=coefficient of relatedness
 coefficient of relatedness: the degree to which you are genetically
related to your kin
 your parents have a CoR of .5, because you share half their
genes
 your uncle has a CoR of .25, because you share a quarter of his
genes
 identical twins have a CoR of 1, because they are perfect genetic
copies
 you are more likely to help your brother than your cousin, because your
brother has a higher CoR than your cousin
 this explains why some animals are willing to help children that aren't
their own
~~~~~~~~~~~~~~~~~~~~~
 humans make these decisions too (again, subconsciously)
o Madsen et al. conducted this experiment in 2007:
 had subjects stand in an uncomfortable squatting position
 for every 20 seconds they remained in that position, the experimenters gave
them money
 subjects were divided into several conditions based on who the money went to
 for one condition, subjects were told that they would receive the money
directly
 for another condition, subjects were told the money would be given to
their parents
 grandparents, cousins, best friends, a charity, etc.
 as CoR decreased, so too did the amount of time subjects were willing to remain
in the squatting position
 subjects held the position the longest when the money went directly to
them
 charity came in last place, followed closely by best friends
 conclusion: kin selection motivates human behavior

7.  recap of what fitness and inclusive fitness mean:
o fitness: reproductive success as measured by the number of offspring you have
o inclusive fitness: reproductive success as measured by the number of offspring you and
your kin have with respect to your kin’s CoR
 sexual selection: if a gene makes you more likely to secure a mate, it will probably get passed
down, even if it doesn't contribute to your survival
o sexual selection is often reflected in an animal's secondary sex characteristics (chest
hair, deep voice, etc.)
o some traits are selected even when they make survival more difficult
o think of a peacock's tail feathers
 they slow the peacock down, making it more difficult to survive, but they still
help him attract peahens
o fighting between male seals is another example of sexual selection
 fighting takes a lot of calories, and it may lead to death, but male seals still fight,
because it helps them secure territory and mates
o the red-backed spider plucks a "song" on the female's web to secure its mate
 this talent is in no way related to survival
 the female red-backed spider tries to eat the male regardless of how good the
"song" was, so this is clearly a dangerous behavior
 sexual selection can lead to great divergence within a species
o for example, the bluegill sunfish practices cuckoldry
 female sunfish are attracted to big males with large territories (called parental
males)
 not all males are big enough to secure attractive territories, but they still find a
way to reproduce
 shortly after a female lays her eggs, these smaller males (the cuckolders) will
swoop in and fertilize them before the parental males can
 if a parental male thinks the cuckolder fertilized most of the eggs, he will
destroy the whole clutch
 but some of the parental males end up raising the cuckolder's offspring
 cuckolders don't usually fertilize as many eggs as the parental males, but their
behavior is still selected for
 a cuckolder doesn't have to be big to reproduce, so he can start
reproducing earlier
 if a female can't find a good enough parental male, she may choose a
mate who is likely to be cuckolded
 the females would rather produce skilled cuckolders than weak
parental males
 to recap:
o organisms bring their genes into future generations via...
 pre-reproductive self-preservation (AKA survival)
 successful reproduction
 helping kin survive and reproduce
o genes that support these things are usually passed down, sometimes indirectly (kin
selection)
o genes that don't support these things are usually eliminated
o each new generation receives the subset of genes from the previous generations that
succeed in these endeavors

8. o for the fish example, neither type of sunfish male can be eliminated from the
population, because both males have genes that allow for survival and reproduction
 other important concepts:
o cultural evolution: changes in the behavior of a species that occurs over generations but
isn't related to genetics
 cultural evolution can also occur within generations
 in complex species like humans, it is easy for a whole generation to change its
behavior without genetic evolution
 learning, imitation, and language all facilitate cultural evolution
o evolutionary lag: our culture and environment changes more quickly than our genes
 instinctive behaviors conflict with cultural norms
 the biggest example is our diets; our instincts tell us to eat as many calories as
possible, because we evolved in an environment where we could never be sure
of our next meal
 nowadays, we are surrounded by calories; this new environment
conflicts with our instincts
 hopefully we will evolve to eat high-calorie foods less often
 evolution of emotions
o emotions: a predisposed reaction to a certain event
 elicited by social and environmental experiences
 different emotions lead to different behavior
o nature vs nurture
 do we learn our emotions, or are they instinctive? before we can answer this
question, we have to answer these:
 are emotions culturally universal?
 Ekman et al. performed this study:
 took pictures of people from North America expressing
different emotions
 showed these pictures to people from other cultures
and asked them to identify the emotions therein
 no matter where the experimenters went, the natives
guessed right more than 60% of the time (usually
around 80% at least)
 most primary emotions (happiness, sadness, fear,
anger, etc.) are expressed the same way in every culture
 are they found in other species?
 yes; Tyler showed us several pictures of animals expressing
emotions
 at one point, he showed us an entire chart of simian facial
expressions
 are they present early in development?
 many emotions are evident in infancy (crying under distress,
smiling under care, etc.)
 preverbal children are very good at expressing themselves
through body language
 are they involuntary?
 have you ever willed yourself to be happy?
 have you ever chosen not to feel sad or angry?

9.  are they stereotyped? are they expressed the same way every time?
would you ever confuse a happy person for a sad person?
 it is rare for someone to look sad when they feel happy or vice
versa
 (by the way, all of these things are related to Darwin's methods for
studying the genetic basis of emotion)
 we answered "yes" to all of these questions, so emotions are more nature than
nurture
 that's not to say nurture plays no role in the development of emotions
 learning and experience tell us whether an emotional reaction is
appropriate or inappropriate
 but even though nurture changes the way we express and perceive
emotions, it cannot change emotions themselves
 you don't learn to feel emotion
Part 3: Genetics, Learning, and Development
 selective breeding, the process of breeding plants or animals based on a favorable trait, began
with agriculture
o you only plant the best crop from each season, and eventually you will have nothing but
amazing crops
o the crops will probably never be perfect, but they will improve from generation to
generation
o back when agriculture was first conceived, nobody thought about genetics; they just
wanted better crops
 nowadays, we can directly manipulate an organism's genes to our specifications
o we can genetically engineer rice with extra vitamin A to make up for nutritional
deficiencies within a population
o we can genetically engineer crops to resist powerful pesticides; this makes farming
much easier
 as an example, Monsanto gave their crops resistance to glyphosate
 farmers can now use as much glyphosate as they need to secure their crops…
 ...so, are humans consuming more glyphosate? does glyphosate hurt us?
 we need to consider the ethics and consequences of genetic manipulation
 when breeding animals, there are other things we need to consider
o the behavior of simple organisms is usually driven by instinct, as opposed to learning
and experience
 humans and other complex animals rely greatly on learning
 learning does not completely override natural instinct, but it plays a very big
part in determining our behavior
o because of this connection between behavior and genetics, you can easily breed
behaviors into certain animals
 dogs are a good example of animals bred for behavior
 some dogs are bred for their loyalty and docility
 other dogs are bred to be hunters and fighters
 a dog that has been bred to behave one way can be trained to behave
differently, but instinct can override training

10.  this is why you occasionally hear stories about pit-bulls
attacking people, even though they were raised as pets
 horses are also bred for docility and calmness
 cattle and sheep are bred to produce the same behaviors
 cats are trained to exhibit inoffensive behavior and enjoy human contact
 lab rats are bred to be unaggressive, comfortable around humans, and tolerant
of confined spaces
 types of instinctive behavior:
o reflex: an innate, involuntary stimulus response
 reflexes can be simple (knee-jerk) or complicated (a cat righting itself while
falling)
 if a reflex becomes very complex, it stops being a reflex, and starts being
something else: a fixed action pattern (defined later)
 reflexes found in adult humans:
 breathing
 blinking
 shivering in the cold
 pulling hands away from hot surfaces
 knee-jerk
 salivation
 jumping when startled by a loud noise or sudden movement
 (all of these reflexes help us survive)
 reflexes found only in human infants:
 suckling when the cheek is stroked
 Babinski reflex: fanning toes when the sole of the foot is touched
 if this reflex does not disappear within the first few years of life,
it could indicate a neurological disorder
 for adults, there should either be no response, or we should curl
our toes down
 Moro reflex: throwing out the arms when startled
 the child may be trying to grasp something, presumably their
mother
 Palmer grasp: grabbing any object placed in the baby's palm
 again, the child may be grasping for the mother
 kicking feet out when held just above the ground
 tonic neck reflex: if you tilt a baby's head to one side while they are
lying on their back, the baby will stick one arm out and bend the other
back
 keeps the baby from rolling accidentally
 (if any of these reflexes are present in older children, it could indicate
developmental problems)
o fixed action pattern (FAP): instinctive, coordinated behaviors too complex to be
considered reflexes
 the term "fixed action pattern" has recently come under criticism, because it
implies that the action is always rigidly stereotyped, which it isn’t
 modal action pattern is the preferred term
 examples of FAPs in less complex organisms:
 grooming

11.  nest-building
 a pregnant mouse will build a nest for its offspring even if it was
raised without a nest
 swimming
 hissing or growling when enraged
 traits that most FAPs have in common:
 stereotyped: FAPs happen the same way, no matter where, when, or in
whom they occur
 all cats groom themselves the same way
 independence from immediate external stimulation; not all FAPs
require stimuli
 many FAPs occur long after the stimulus was presented
 the FAP does not change with the environment; when the FAP
starts, it doesn't usually stop
 behaviors not classified as FAPs are directed by
external/environmental conditions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 spontaneous: the timing, duration, and intensity of an FAP are not
determined by external stimuli or environmental conditions
 if it's been a while since the last time an animal performed a
certain FAP, that FAP will probably happen soon, and when it
happens it will be very intense
 for example, when carbon dioxide builds up in a male
stickleback fish's nest, it fans out the CO2 with its fins
 if a male stickleback is forced to go a long time without fanning
the nest, it will start fanning again as soon as possible and with
gusto
 independence from individual learning; if it's a learned behavior, it's not an FAP
o the FAP is not affected by learning experiences or changes to the environment during
development
o remember the thing about pregnant mice and nest-building?
 the genetics of behavior:
o as stated earlier, we can breed animals to exhibit certain motivations and emotions
o studies in humans have shown that behavior can be inherited
o some animals exhibit simple behaviors that can be traced to a single gene
 Whitney performed this experiment in 1969:
 C57 mice rarely vocalize
 JK mice vocalize often
 Whitney bred C57 mice and JK mice together
 56% of the crossbred f1 generation vocalized, compared to 3% of the
C57 and 68% of the JK
 according to Mendelian inheritance, this is what you would expect to
happen if the behavior was influenced by a single dominant gene
 Van Abeelen performed this experiment in 1967:
 Waltzer mice are observed to dance
 two Waltzers will produce a litter consisting entirely of dancing mice
 when Waltzers are bred with the non-Waltzing f1 generation, it
produces no dancing mice

12.  when two f1's are bred, 25% of offspring can dance
 Mendelian ratios suggest a single recessive gene
 the aforementioned studies were really exciting at the time
o complex behaviors are usually influenced by multiple genes
 Lagerspetz conducted this study in 1964:
 male mice were selectively bred for or against aggression over seven
generations
 only the most/least aggressive males were allowed to breed
 by the end of the experiment, there was a big difference between the
aggressive mice and unaggressive mice
 shows that aggression is genetic
 DeFries performed this experiment in 1978:
 mice were selectively bred for or against the tendency to explore open
spaces over thirty generations
 by the end of the experiment, mice in the high-exploration condition
were much more explorative than the control group
 mice in the low-exploration condition would freeze up in open spaces
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Plomin conducted this study in 1994:
 he compared monozygotic and dizygotic twins on a number of different
traits
 if one of the twins had Alzheimer's, autism, major affective disorder, a
reading disability, or alcoholism, the other twin was more likely to also
have that condition if the twins were monozygotic
 twins were raised in the same environment, so it's hard to say whether
that affects the conditions
 learning and flexibility
o learning helps us adapt to a complex, changing environment
o with learning, we can adapt to changes in the environment within one lifetime
o the ability to learn is driven by genetics
o some instincts depend on the ability to learn
 for example, many animals are driven to explore their environments
 this drive would be useless and dangerous if not for learning
 animals explore because they want to learn where to find resources and
how to avoid predators; they would not receive these benefits if they
couldn't learn
 play is another behavior influenced by learning
 many species engage in rough-and-tumble play, which teaches them
how to fight or defend themselves against predators
 simple forms of learning:
o habituation: the longer you are exposed to a stimulus, the less you notice it
o sensitization: the longer you are exposed to a stimulus, the more noticeable it becomes;
you are made sensitive to the stimulus
 classical conditioning: an animal learns to associate one stimulus with another and behaves
accordingly when either stimulus is presented
o the most famous example of classical conditioning is Pavlov's dog
 every time Pavlov fed his dog, he rang a bell
 the dog learned to associate the bell with food

13.  eventually, all Pavlov had to do was ring the bell, and the dog would salivate as
though in the presence of food
o types of stimuli and behavioral responses:
 unconditional stimulus (US): the original stimulus (food)
 unconditional response (UR): the behavioral response to the US (salivation)
 conditional stimulus (CS): the stimulus that becomes associated with the
original stimulus (bell)
 conditional response (CR): when the animal learns to associate the CS with the
US, it exhibits the UR when exposed to the CS (salivation in response to the bell)
 the CR is usually the same as the UR, but not always
o the three steps of classical conditioning:
 before conditioning: the US produces the UR; the CS isn't even a factor
 during conditioning: the US is repeatedly paired with the CS
 after conditioning: eventually, the CS will produce the CR, usually the same as
the UR
o some types of conditioning are so powerful, they only take one trial to set in
 Garcia conditioned animals to associate food with sickness
 if you irradiate an animal, it gets sick
 Garcia irradiated animals shortly after feeding them a specific food
 from then on, the animals refused to eat the food; just seeing it made
them sick
 this only took one trial
o humans can be conditioned to elicit specific emotional responses when exposed to
stimuli
 traumatic, sexual, and gratifying stimuli are very easily paired with emotions
 war veterans often suffer from PTSD
 gunfire is a good example of one-trial conditioning in humans
 people who have been shot at learn to associate loud, sudden
noises with life-threatening situations
 if the person you're dating always wears the same perfume, you will
associate that perfume with that person and the feelings they elicit in
you
 even if you smell the perfume in a mall years after breaking up,
it can still trigger positive emotions
 instrumental (operant) conditioning: an animal learns to respond to a stimulus in a certain way,
because that response is somehow reinforced
o dimensions of instrumental conditioning:
 positive: a stimulus is presented following a response
 negative: a stimulus is withdrawn following a response
 reinforcement: the presentation or withdrawal of a stimulus causes the
behavior to increase in frequency
 punishment: the presentation or withdrawal of a stimulus causes the behavior
to decrease in frequency
o types of instrumental conditioning
 positive reinforcement (usually just called reinforcement): a stimulus is
presented, increasing the frequency of a behavior
 for example, a dog can be trained to sit on command if you give it a
treat every time it sits when you tell it

14.  negative reinforcement (escape): a stimulus is withdrawn, increasing the
frequency of a behavior
 for example, if you electrocute a mouse until it pulls a lever, the mouse
will learn to pull the lever every time it gets shocked
 positive punishment (usually just called punishment): a stimulus is presented,
decreasing the frequency of a behavior
 for example, if you spray a cat with water every time it scratches the
sofa, it will eventually learn to stop scratching
 negative punishment (omission): a stimulus is withdrawn, decreasing the
frequency of a behavior
 for example, if you take away a child's toy after he/she misbehaves, the
child will eventually learn to stop misbehaving
o basically, animals repeat behaviors that lead to positive outcomes and curb behaviors
that lead to negative outcomes
 extinction: if a conditioned behavior/response is no longer reinforced, that behavior will
eventually cease
o if you reinforce a behavior every time it is performed, extinction happens more quickly
o for example, if you reward a dog every time it sits on command, and then you suddenly
stop rewarding the dog, it will stop sitting on command
o but if you gradually decrease the frequency with which you reward the dog, it will never
stop sitting, even after you stop feeding it entirely
 the physiology of reinforcement:
o rewards that occur in nature (food, drink, sex, etc.) are associated with increased
dopamine activity in the nucleus accumbens
o other rewards (money, etc.) will trigger the same response in humans
 conditioning doesn't always override FAPs
o FAPs are so deeply instinctive that they can occur even after conditioning
 you can train a pit-bull not to be aggressive, but the pit-bull may instinctively
return to those behaviors
 for example, mice instinctively avoid bright lights, even when it is in their best
interest to run towards a light
 in one experiment, mice were electrocuted every time a light shone into
the cage
 the mice could avoid the shock by running to the other side of the cage
 but if a light shone over the opposite end of the cage, the mice would
not run towards it, even though they knew they would get shocked
 Breland and Breland conducted this study in 1961:
 they were hired to train an animal (either a pig or a racoon) to put a
coin in a piggy bank
 here's how they planned to do it:
 reward animals for picking the coin up
 ...then reward them for carrying the coin to the bank
 ...then reward them for dropping it in the bank
 unfortunately, they couldn't even get passed the first part of the plan
 racoons would just roll the coin in their hands; it's what they
instinctively do with food
 pigs would drop the coins and "root" into the ground, looking
for more

15.  no matter what Breland and Breland tried, they could not train the
animals to work with the coins
 two more concepts related to learning:
o vicarious learning: learning through imitation
 also called modeling and contagion
 the animal observes a behavior, repeats it, and in repeating learns to perform
the behavior
 caused by mirror neurons
 offspring learn from their parents through imitation
o incentives/disincentives: humans do not need to have a reward or punishment in front
of them to be conditioned; all we need is the promise or representation of a reward
 for example, humans seek out money, even though money isn't something we
need in itself
 ...but money represents the things we need, so we continue to seek it out
Part 4: General Physiological Perspective (with special thanks to
Stephanie Williams, Jamie Gallagher, and an anonymous
contributor!)
 the human nervous system can be split into two sections: the central nervous system (CNS) and
the peripheral nervous system (PNS)
o the CNS includes the brain and spinal cord
o the PNS includes everything else
o both divisions of the nervous system are important to motivation and emotion
 for example, the PNS regulates many of the physical effects of emotion
(sweating, heart rate, stomach dropping, etc.)
 the components of the CNS are explained in detail here:
o spinal cord
 for the most part, the spinal cord is just a tract through which the brain sends
and receives information
 it also processes certain simple reflexes
o hindbrain
 contains the medulla, pons, and cerebellum
 the medulla controls our cardiac and respiratory systems; it makes us breathe
and regulates our heart beat
 it also causes vomiting and determines the constriction of blood vessels
 the pons maintains a wide variety of functions, including chewing, swallowing,
saliva secretion, tear production, facial expressions, eye movement, and balance
 the cerebellum helps us coordinate complex movements
 none of these parts are too involved in motivation or emotion
o midbrain
 contains the tectum and tegmentum
 the tectum processes auditory and visual sensory information
 we aren't completely sure what the tegmentum does, but it is probably involved
in eye movements

16. o forebrain
 contains the thalamus, hypothalamus, pituitary glands, basal ganglia, limbic
system, cerebral cortex, and many other parts…
 the thalamus can be thought of as a switchboard that receives sensory data and
sends it to other parts of the brain
 also determines our sleep/waking cycles
 the collection of structures known as the limbic system is located on
either side of the thalamus and maintains a variety of functions related
to motivation and emotion
 The hypothalamus controls a variety of metabolic processes, such as hunger,
thirst, sleep, fear, anger, body temperature, and parental urges
 It synthesizes and secretes hormones that control the behavior of the
pituitary gland
 the pituitary gland secretes hormones that control several physiological
processes, the most notable of which are related to reproduction and physical
growth
 the hypothalamus and the pituitary gland are both part of the
endocrine system, which controls the body's supply of hormones
 the basal ganglia is heavily involved in the brain's "reward" system
 the cerebral cortex contains several lobes that process sensory information and
help us form associations between objects and concepts
 it also sends information between the thalamus and the basal ganglia
 these structures are important, but not all of them are needed to survive
o cerebellar agenesis: a condition where the cerebellum fails to develop, leaving a
person's brain without its primary means of coordinating movement
 in 2014, Yu, Jians, Sun, and Zhang wrote a case study about a woman with
cerebellar agenesis
 she is very clumsy, and she gets dizzy and nauseous easily, but other than that
she's okay
 right now, she is the only person we currently know of who lives a healthy,
normal-ish life without their cerebellum
 perhaps, due to the plasticity of the brain, other nearby parts took over the
cerebellum's function?
o of course, some parts of the brain are vital; without the brainstem, for example, you
would certainly die
 the structure of the brain reflects its evolution
o our brain is similar to that of other mammals in several ways
 we have many parts in common, all sharing the same function and structure,
although the parts themselves are organized differently
o there are a few noticeable differences between the human nervous system and the
systems of other mammals:
 first, other animals tend to rely more on their olfaction (sense of smell), and this
is reflected in their neuroanatomy
 our brains also differ in terms of size and complexity
 animals lack some of the parts we have and vice versa
 for example, while we have a cerebral cortex, sharks and frogs have a
neocortex
o our posture also tells us something about how our brains evolved

17.  the shape and angle of our brain and brainstem is suited to a bipedal lifestyle
 quadrupedal animals have straight brainstems to compliment the flatness of
their backs, whereas our brainstem is pointed downward
 some scientists argue that human posture provides more space for the brain to
grow; this is not yet proven
 we will spend a lot of time talking about these parts of the human nervous system:
o the limbic system
 as stated above, the limbic system is a collection of parts that work together to
influence our motivations and emotions
 some parts of the limbic system are more heavily involved in motivation and
emotion than others
 we will discuss the limbic system in greater detail later
o the hypothalamus
 the hypothalamus is located right above the pituitary gland
 again, as stated above, it secretes hormones that control the pituitary
gland's function
 peptide hormones play an especially big role here, but more on that
later
 the hypothalamus responds to several stimuli:
 light
 to be more specific, the hypothalamus changes its function
based on an organism's photoperiod
 photoperiod: the amount of time each day an organism is
exposed to light
 the longer the photoperiod, the greater the duration of activity
in the hypothalamus
 when the photoperiod is short, people often become sad or
depressed, which could mean that the hypothalamus plays a
role in seasonal affective disorder
 olfactory stimuli
 the hypothalamus is thought to respond to pheromones
(pheromones will be explained next lecture)
 steroid hormones (again, next lecture)
 neural information
 the CNS and the PNS both influence the hypothalamus
 the hypothalamus is innervated by several other brain regions
 input from the autonomic nervous system (more on that later)
 various peptide hormones (next lecture), along with other substances
found in the blood, but only if they can cross the blood brain barrier
o the autonomic nervous system (ANS) contributes to many of the physical sensations
associated with our emotions
 the ANS is a huge component of the PNS
 it innervates all major organs in the body, as well as several glands
o there are three major divisions of the ANS: the enteric nervous system (ENS), the
sympathetic nervous system (SNS), and the parasympathetic nervous system (PSNS)
 the ENS influences the gastrointestinal system; it's not very important to
motivation and emotion

18.  the SNS and PSNS both stem from the spinal cord, but they are involved in
different nervous processes despite innervating the same organs
 the SNS connects to the thoracic and lumbar nerves, while the PSNS
connects to the cervical and sacral nerves
 figure 4-6 in the textbook tells you where these nerves lead
 the SNS dictates our fight/flight responses, while the PSNS controls our
rest/digest functions
 to put it another way, the SNS generates and expunges energy, while
the PSNS conserves and collects energy
o here's a more detailed list of what the SNS does when active:
 increases heart rate, respiratory rate, and blood pressure
 inhibits digestion, reduces blood flow to the digestive tract and skin
 increases blood flow to the muscles and lungs
 dilates the pupils
 causes piloerection (goose bumps)
 can sometimes cause spontaneous urination and defecation in moments of
intense arousal
o here's a list of what the PSNS does when active:
 decreases heart rate, respiratory rate, and blood pressure
 promotes digestion by increasing blood flow to the digestive tract
 stimulates secretion of saliva
 regulates sleep and sexual behaviors
o the adrenal glands
 the adrenal glands should really be thought of as two pairs of glands, because
each gland contains two semi-glands: the adrenal medulla and the adrenal
cortex
 the adrenal medulla is the core of the adrenal gland; it secretes catecholamines
when the SNS activates
 the adrenal cortex surrounds the medulla; it secretes steroids in response to
chemical stimulation, especially adrenocorticotropic hormone (ACTH) from the
pituitary
 the cortex has three layers:
 the first layer (reticularis) produces androgens, like testosterone and
DHEA
 the second layer produces aldosterone, which regulates blood pressure
and kidney activity among other things
 the third layer produces cortisol, which causes stress in humans
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 hormone: a substance released into the bloodstream that communicates with receptors at
distant site(s)
o the life of a hormone:
 a cell secretes the hormone into the bloodstream
 the hormone travels through blood vessels until it finds its target cell
 the hormone interacts with the cell's receptors, thus changing, activating, or
inhibiting the target cell's function
 neurotransmitter: a substance released into the synapse when a presynaptic neuron fires
o neurotransmitters are picked up by receptors on the postsynaptic neuron's dendritic
membrane

19. o neurotransmitters either increase or decrease the chance that the postsynaptic neuron
will fire
 neuromodulator: similar to a neurotransmitter, except it affects multiple neurons in the brain at
once
o neurotransmitter activity happens on a neuron-to-neuron basis, while neuromodulator
activity occurs all over the brain
o Neuromodulators travel through pathways in the brain to affect several places at the
same time
o the cerebrospinal fluid and ventricular system help determine where neuromodulators
go and how they work
 pheromone: any substance excreted by one individual that affects another individual's behavior
o most people think of pheromones as relating to sex/mating, but they can affect
behavior in all sorts of ways
o pheromones from one species are only meant to work on that species
 there could be some inter-species pheromone effects, but it usually doesn't
happen
 a pheromone's effect on one species will probably be different from its effect on
another species
 there are four main classifications of hormones/neurotransmitters: steroid hormones, peptide
hormones, monoamine hormones/neurotransmitters, and acetylcholine (ACh)
o steroid hormones
 small, lipid-soluble molecules that travel all throughout the body
 The steroid hormones' lipid-solubility makes it easy for them to get
where they need to go, because most cells have lipid membranes
 derived from cholesterol
 very slow
 they are excreted slowly, they act slowly, and they leave the body
slowly
 steroids can spend hours, days, or even months in the body before they
leave
 if steroids were water-soluble, they would leave the body much more
quickly, because water-soluble chemicals dissolve quickly in urine
 they usually act on intracellular receptors (receptors inside the cell), though
certain steroids act on extracellular receptors instead ( receptors on the cell
membrane)
 examples of steroids and the organs that produce them:
 the gonads produce androgens (like testosterone), estrogens, and
progesterone
 the adrenal cortex acts as a source of androgens, estrogens,
mineralocorticoids, and glucocorticoids (like cortisol)
 technically speaking, the adrenal cortex can only produce
cortisol, but it uses that cortisol to synthesize other hormones
 cortisol has 21 carbons; every time you remove a carbon, it
becomes a different hormone
 for example, testosterone has 19 carbons, so for the
adrenal cortex to make testosterone, all it has to do is
take 2 carbons away from cortisol

20.  but if the adrenal cortex can only produce cortisol, how do we know if
it's really producing all those other steroid hormones? how do we know
they aren't coming from somewhere else?
 because even after you take away all other possible sources of
those steroid hormones, they are still present in the body
 for example, a female mouse will still produce steroid
hormones after her ovaries have been removed
 so how do we know the adrenal cortex can only produce cortisol? after
all, those other hormones are clearly found in the adrenal cortex…
 we know because of experiments performed on something
called aromatase
 aromatase is an enzyme that uses androgens to synthesize
estrogens
 if you inject an aromatase inhibitor into the adrenal cortex, it
no longer produces estrogens
 this shows that all estrogens in the adrenal cortex are
synthesized from androgens; it doesn't produce its own
o peptide hormones
 chains of amino acids derived from proteins
 very fast-acting
 within seconds or minutes, they leave the body
 amino acid chains are easy to put together and break apart, so they are
secreted and absorbed very quickly
 peptide hormones are also water-soluble, which makes them even
easier to break down
 act on extracellular receptors
 peptide hormones are often too large to pass through the cell
membrane
 examples of peptide hormones and the organs that produce them:
 the pituitary gland is divided into two halves, each of which produces its
own set of hormones
 the anterior pituitary gland produces ACTH, beta endorphin,
LH, FSH, prolactin, and many more
 the posterior pituitary gland produces oxytocin and vasopressin
(ADH)
 the hypothalamus produces CRH, GnRH, and neuropeptide Y (NPY)
among others
 as stated in the previous lecture, the hypothalamus uses
hormones to act on the pituitary gland
 however, these hormones only act on the anterior pituitary, not
the posterior
 the hypothalamus does innervate the posterior
pituitary, but through nerve signals, not hormones
 of course, not all hormones produced by the hypothalamus are
used to manipulate the pituitary gland; which ones do?
 NPY
 pretty much anything with "releasing" in its name
 the gut produces cholecystokinin (CCK) and ghrelin

21.  the pancreas produces insulin and glucagon
 adipose produces leptin
 CCK, ghrelin, insulin, glucagon, and leptin will all be explained in
the next chapter
 the brain's ventricular system relays many hypothalamic and pituitary
hormones
 the limbic system, hypothalamus, and brainstem all contain peptide
hormones
o monoamine hormones and neurotransmitters
 like peptide hormones, but derived from single amino acids, rather than long
chains
 this makes them much smaller than peptide hormones
 still fast acting, still excreted quickly, still water-soluble, still act on extracellular
receptors
 examples:
 the adrenal medulla produces catecholamines like epinephrine and
norepinephrine (also called adrenaline and noradrenaline)
 epinephrine and norepinephrine are also used as
neurotransmitters
 the pineal gland produces indoleamines, like melatonin
 melatonin regulates your sleep cycle
 the more melatonin enters your system, the sleepier
you become
 when it's dark out, the pineal gland secretes more melatonin;
when it's bright out, not so much
 so be careful not to expose yourself to too much light in the
evening, or it could affect your circadian rhythm
 this is why pharmaceutical companies sell melatonin
supplements: for people who need to re-adjust their sleep-
cycles due to jet lag or staying up too late
 monoamine neurotransmitters are also derived from single amino acids
 glutamate, GABA, histamine, and glycine are all examples of monoamine
neurotransmitters
 there are two broad categories of monoamine neurotransmitters, both of which
are derived from different amino acids:
 catecholamines are synthesized from tyrosine
 tyrosine is synthesized into dopamine, which can then be
synthesized into norepinephrine, and then epinephrine
 as stated earlier, the adrenal medulla also produces the
catecholamines adrenaline and noradrenaline (same structure
as norepinephrine and epinephrine), but these are used as
hormones, not neurotransmitters
 indoleamines are synthesized from tryptophan
 tryptophan is synthesized into serotonin, which can then be
synthesized into melatonin
 the pineal gland also produces melatonin, but there it is used as
a hormone
 both types of monoamine transmitters have their own sets of neural pathways

22.  catecholamines have dopaminergic and noradrenergic pathways
 dopaminergic pathways:
 dopamine cell bodies are concentrated in two areas: the
substantia nigra and the ventral tegmental area
 both of these parts are in the brainstem
 axons from cell bodies in the substantia nigra ascend through
the medial forebrain bundle (MFB) to the striatum, an
important part of the limbic system
 axons from cell bodies in the ventral tegmental area also ascend
through the MFB; they end up in either the nucleus accumbens
(where dopamine is used to control reward mechanisms) or the
forebrain
 dopamine also performs certain actions in the posterior
pituitary, but not the anterior pituitary
 noradrenergic pathways:
 noradrenaline cell bodies are concentrated in the locus
coeruleus of the brainstem
 axons from these cell bodies ascend through the MFB into the
neocortex, then disperse throughout the limbic system, as well
as the cerebellum, spinal cord, and cortex
 this is called the neocortex circuit
 indoleamines have serotonergic pathways
 serotonergic pathways:
 serotonin cell bodies are concentrated in the raphe nuclei
 their axons ascend through the MFB into one of these
destinations: the thalamus, basal ganglia, limbic system, or
neocortex
 axons that enter the neocortex travel through the same circuit
as noradrenaline, taking them to the cerebellum, spinal cord,
and cortex
 a special note on serotonin:
 serotonin affects both the central and peripheral nervous
systems, but serotonin from the CNS does not mix with
serotonin from the PNS
 this is why antidepressants, specifically SSRI's (selective
serotonin reuptake inhibitors), only affect serotonin in the
synapses, not the brain
 just to make things perfectly clear, the synapses are
part of the PNS and the brain is part of the CNS, so
serotonin from either shouldn't mix
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 but you can't synthesize monoamine hormones and neurotransmitters without monoamines!
how do all those amino acids get to the brain in the first place?
o with help from the large neutral amino acid transporter
o tryptophan, tyrosine, phenylalanine, methionine, and branch-chained amino acids are
all carried by the large neutral amino acid transporter
 without it, none of these amino acids would make it past the blood-brain barrier
 this is usually the brain's only source of amino acids

23. o the amino acids listed above "compete" for access to the transporter
 if one amino acid gets disproportionate access, it causes a shortage of all the
others
 for example, too much phenylalanine could cause a shortage of tryptophan,
which would then lead to serotonin deficiency
 tryptophan and phenylalanine are both metabolized from food
 tryptophan is obtained from foods like chocolate and red wine, both of
which are highly sought-after
 of course, high levels of tryptophan lead to high levels of serotonin, so
chocolate and red wine are very rewarding foods
 conversely, serotonin levels plummet after eating food without
tryptophan
 phenylalanine is found in aspartame, a popular artificial sweetener, and
is much easier to metabolize than tryptophan
 so if you have too much soda, it could drastically affect your serotonin
levels
 acetylcholine (ACh)
o ACh is an important neurotransmitter in the autonomic nervous system and certain
parts of the brain
o it travels through both the sympathetic and parasympathetic nervous systems
 in the PSNS, ACh travels all the way from the spinal cord's preganglionic neurons
to the body's postganglionic neurons
 …but in the SNS, ACh only travels through the preganglionic neurons; the
postganglionic neurons receive norepinephrine instead
 why? because otherwise, the postganglionic neurons couldn't tell the difference
between signals from the SNS and PSNS
 if both the SNS and PSNS used ACh, the body would get confused
 but since the SNS switches to norepinephrine, postganglionic neurons can tell
which signals come from which system
Part 5: Hunger, Thirst, and Elimination
 As you can imagine, thirst is a pretty big motivator
o If you are adequately hydrated, you don't even think about being thirsty
o But as stated in a previous lecture, if you get really thirsty, it becomes all you can think
about
o Thirst is important for maintaining homeostasis
 if you drink too little water, your body motivates you to drink more by making
you thirsty
 drinking too much water can also have consequences, especially if you don't
have enough electrolytes; your blood becomes diluted, and your neurons have
trouble firing
o there are two types of water deficiencies:
 extracellular thirst: your body does not have enough extracellular fluid
 extracellular fluid is any fluid located outside of the body's cells
 found in blood vessels, cerebrospinal fluid, body cavities, etc.
 accounts for 1/3 of the total water in the body

24.  extracellular thirst is induced by perspiration, blood loss, diarrhea, and
heavy menstruation, all of which remove extracellular fluid
 extracellular thirst causes the volume of your blood to decrease, which
in turn decreases blood pressure
 here's how extracellular thirst works:
 it starts with a drop in blood volume
 as your blood pressure goes down, the baroreceptors in your
kidneys, which respond to changes in blood pressure, are
activated
 the kidneys start to produce an enzyme called renin
 renin synthesizes angiotensin, a peptide hormone that causes
vasoconstriction (the closing of the blood vessels)
 this boosts your blood pressure artificially, but it doesn't
really solve the problem
 renin gets its angiotensin from a chemical called
angiotensinogen, whose only purpose is to be
converted into angiotensin (hence the name) when
blood pressure drops
 there are four kinds of angiotensin, but angiotensin 2 -
the one we're talking about - is the only one you really
need to remember
 angiotensin 1, which helps control the amount
of angiotensin 2, is also somewhat important
 angiotensin also acts on the adrenal cortex to produce
aldosterone, which causes the kidneys to reabsorb sodium
 it acts on the pituitary as well, producing vasopressin (also
known as antidiuretic hormone), which causes the kidneys to
reabsorb water
 but wait! angiotensin is a peptide hormone! how could possibly it act on
the hypothalamus and pituitary, when peptide hormones are too large
to cross the blood-brain barrier?
 the subfornical organ, a part of the brain which lacks a blood-
brain barrier, reacts to angiotensin
 neurons in the subfornical organ project into the hypothalamus,
which then influences the pituitary
 the hypothalamus causes the sensation of thirst
 the subfornical organ also contains osmoreceptors, which
detect changes in the body's osmotic pressure
 cellular thirst: your body does not have enough intracellular fluid
 intracellular fluid is any fluid located inside the body's cells
 accounts for 2/3 of the total water in the body
 cellular thirst is induced by excess salt consumption
 cellular thirst also comes about when someone loses so much
extracellular fluid through perspiration or blood loss, the body's osmotic
pressure pulls water out of cells
 most of the thirst we experience is caused by excess salt
consumption

25.  but both salt consumption and severe fluid loss lead to an
increase in extracellular sodium
 here's how it works:
 excess sodium creates osmotic pressure that pulls water out of
the body's cells
 basically, water moves from an area of high
concentration (inside the cells) to an area of relatively
low concentration (outside the cells, where there is too
much salt to be counterbalanced by extracellular fluids)
 given the nature of the lipid bilayer, it's much easier to
pull water out of the cells than it is to pull sodium into
the cells
 osmoreceptors around the hypothalamus near the third
ventricle detect this change in osmotic pressure
 the osmoreceptors sample the fluid balance of the
blood and cerebrospinal fluid
 the hypothalamus stimulates thirst
 osmoreceptors are the brain's only way of knowing whether the body's
cells are thirsty
 if you inject a rodent with distilled water near its
osmoreceptors, the rodent will show signs of water-
overconsumption; it will refuse to drink, even when its cells are
actually thirsty
 the reverse is also true: if you inject saline near osmoreceptors,
the rodent starts drinking like crazy
o a few more concepts related to thirst:
 prandial drinking: drinking water because you feel thirsty immediately after
eating food
 when you're eating, you naturally want to drink at the same time
 the body is not yet overloaded with sodium, so there shouldn't be any
reason to drink…
 …but since the body will need to drink water eventually, it might as well
get started now
 prandial drinking may be a learned behavior; it is more convenient to
sip water during a meal than to gorge on water afterwards
 cessation of drinking: people only drink enough water to replenish their fluids;
no more
 it isn't often that someone accidentally drinks too much water
 the thing is, by the time we stop drinking, our fluid balance still hasn't
technically been restored; how do we know when to stop?
 as with prandial drinking, cessation could be anticipatory
 cessation is also thought to be derived from receptors in the mouth,
esophagus, and stomach, as well as from the swallowing reflex
 hunger is another vital motivator
o satiety, the feeling of fullness, is also important; without satiety, we would eat ourselves
to death
o of course, plenty of people do eat themselves to death nowadays…

26.  we evolved in an environment where no one could be sure of their next meal,
so it was safe to overeat every now and then
 today, most people have no trouble finding calories and sodium, but we still
overeat
o hunger and satiety make up two metabolic phases: feeding and fasting
 The feeding phase (absorptive) occurs shortly after eating and is triggered by
the parasympathetic nervous system
 the pancreas releases insulin, which promotes the absorption of
glucose - the body's most accessible means of storing energy - into fat
tissue
 the body is trying to store excess glucose in the form of longer-lasting
glycogen and fatty acids
 The fasting phase (utilization) starts if you go a long time without a meal and is
triggered by the sympathetic nervous system
 the pancreas releases glucagon, which breaks glycogen into glucose
 the body isn't getting any glucose from food, so it has to liberate the
energy in its stores
 if you lose too much glycogen while fasting, your body will switch to
ketone bodies and eventually fatty acids as a source of energy
 when the body switches to fatty acids, your hunger may
temporarily subside
 the reason you feel hungry after waking up is because your body is in
the fasting phase
o stomach distension, stomach pangs, and "growling" are usually associated with strong
hunger
o when the stomach is full, however, your hunger will subside
 you can stimulate the feeling of satiety in a rodent by blowing up a balloon in its
stomach
 one of the more common surgeries for weight loss is to remove part of the
stomach and staple it shut, reducing hunger
o these two chemicals are strongly associated with hunger and satiety:
 ghrelin is associated with hunger
 it is secreted by the intestines, the pancreas, and the epithelial cells
lining the stomach
 empty stomachs secrete more ghrelin, which helps explain why filling
the stomach reduces hunger
 ghrelin levels rise in the blood while fasting
 cholecystokinin (CCK) is associated with satiety
 if you inject a rodent with CCK, it does not seek food
 the intestines secrete CCK when they are filled with food
 there are CCK receptors throughout our nervous system, the most
important of which are found directly on the hypothalamus and through
the vagus nerve
o other factors that influence appetite:
 glucostatic factors:
 intracellular glucose (glucose found inside of the cells) is very important
for controlling hunger

27.  when your cells run out of glucose, the pancreas secretes
glucagon, the stomach secretes ghrelin, and you become hungry
 conversely, when your blood is filled with glucose (called blood
glucose or blood sugar, different from intracellular glucose in
that it isn't currently being used by the body as a source of
energy), the pancreas secretes insulin, the intestines secrete
CCK, and you become sated (full)
 diabetes: a condition where, no matter how much glucose a
person has in their blood, the pancreas never releases insulin;
that, or the body doesn't respond to insulin properly
 diabetics remain hungry even when their blood glucose
levels are extremely high
 people with diabetes must take insulin shots to regulate
blood glucose and control their appetites
 if a diabetic builds up resistance to insulin, blood
glucose will remain high, and they will continue to feel
hungry
 for comparison, if you inject a healthy person
with insulin, blood glucose will drop, and they
will start to feel hungry (the body interprets a
lack of blood glucose as having not eaten in a
while)
 your brain prefers glucose to all other forms of energy
 when you start running out of glycogen, the brain sucks up as
much glucose as possible
 even after the rest of your body has resorted to ketone bodies
and fatty acids, the brain will still be running on glucose
 we aren't sure if there are glucose receptors in the brain, so how does
the brain measure blood glucose levels?
 the liver does have glucose receptors, and it is connected to the
brain by the vagus nerve
 the liver uses its glucose receptors to tell the pancreas what to
do
 if there's too much glucose in the liver's hepatic portal
vein, it tells the pancreas to release insulin
 to little glucose, and it tells the pancreas to release
glucagon
 lipostatic factors:
 the body contains fatty acids, and those fatty acids are sometimes used
for energy
 …but the body doesn't have any fatty acid receptors, so it can't keep
track of fatty acids
 for a while, scientists had no idea how the body controlled lipid intake
 now they know that leptin, a hormone secreted by adipose tissue, is
responsible
 adipose tissue stores fatty acids, so if you have a lot of leptin, you also
have a lot of fatty acids

28.  leptin reduces your appetite and increases your metabolism; without it,
your body would never make any attempt at burning off excess fat
 mice who can't produce leptin (called OB mice) get really obese,
hence the name
 if you give an OB mouse a shot of leptin, it will stop eating
 some pharmaceutical companies have tried to market leptin as a diet
pill with limited success
 leptin will only curb your appetite if you have a leptin-related
metabolic disorder
 if you give a regular mouse a shot of leptin, it will not stop
eating
 neuropeptide Y
 NPY is thought to cause food-seeking behavior
 it is less active when you are well-fed and more active when you
are hungry
 obesity in humans is linked to excessive NPY
 NPY neurons are found in arcuate nucleus of the hypothalamus, located
at the base of the third ventricle
 if you inject NPY into a rat's hypothalamus, they will eat
ravenously
 chronic stress and a high-fat, high-sugar diet both lead to excessive NPY
 (according to studies done in monkeys)
 genetics also play a role
 interactions between these chemicals:
 leptin inhibits the secretion of NPY in the arcuate nucleus of the
hypothalamus, decreasing food intake
 ghrelin encourages the secretion of NPY in the arcuate nucleus of the
hypothalamus, increasing food intake
 brain physiology:
 the ventromedial hypothalamus causes satiety
 if you electrically stimulate the ventromedial hypothalamus, it
causes aphagia (unwillingness to eat)
 if you lesion the ventromedial hypothalamus, it causes
hyperphagia (overeating)
 the lateral hypothalamus causes hunger
 if you electrically stimulate the lateral hypothalamus, it causes
hyperphagia
 if you lesion the lateral hypothalamus, it causes aphagia
o so, to summarize:
 before a meal…
 insulin is low (not enough blood glucose to stimulate insulin production
in the pancreas)
 glucagon is high (the body needs to break down glycogen for energy)
 ghrelin is high (secreted by an empty stomach)
 CCK is low (the intestines only secrete CCK after receiving food)
 blood glucose is low (blood glucose comes from food, after all)
 leptin is unknown (leptin is released by adipose tissue, the amount of
which cannot be predicted)

29.  NPY is high (ghrelin stimulates production of NPY)
 after a meal…
 insulin is high (lots of blood glucose, so the liver tells the pancreas to
produce insulin)
 glucagon is low (the body needs to store energy, so no need for a
chemical that synthesizes glucose)
 ghrelin is low (the stomach is full; it doesn't produce as much ghrelin)
 CCK is high (food is in the intestines, so they release CCK)
 blood glucose is high (lots of glucose was recently absorbed into the
blood by the intestines)
 leptin is still unknown (one meal won't substantially increase your
adipose tissue)
 NPY is low (no ghrelin, no NPY production)
o psychological fun facts
 the mere odour and sight of food can stimulate hunger
 there are also social influences on feeding behavior
 if other people are eating, you will probably start eating too
 Herman et al. conducted this study in 2003
 told subjects that they were going to taste different kinds of
cookies and rate them
 experimenters also told subjects to rate their hunger
 subjects were divided into two conditions
 the first condition just ate the cookies and made ratings
 the second condition got to see other peoples' ratings
first, including their hunger ratings
 if subjects in the second condition saw that other people rated
themselves as hungry, they too rated themselves as feeling
hunger
 if subjects saw that other people rated themselves as
not hungry, they also rated themselves as not hungry
 but no matter how hungry or not hungry subjects in the second
condition rated themselves, they always ate the same number
of cookies as the first condition
 subjects only adjusted their perception of their own hunger; the
actual desire to eat food didn't change
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 de Castro conducted this study in 1994
o recruited over 500 subjects
o told them to record what they eat, how much they eat, and who they eat with for 7 days
o found that when subjects ate alone, they ate a certain amount of food at a certain pace
o when subjects ate with family and romantic partners, they ate more food, and they ate
it more quickly
o when subjects ate with friends, they also ate more food, but they ate slower
o this study contradicts Herman et al.'s study, because subjects' food intake was
dependent on social influences, not just their own expression/perception of hunger
 humans have an innate appetite for certain kinds of food
o we like sweet foods (with glucose) and salty foods (with sodium)

30. o humans also have a preference for fatty foods, but there isn't enough evidence to call
this preference "innate"
o the preference for sweets is observed in many, many other species
 sweet foods are useful, because they give us easy-to-digest, easy-to-burn
energy with little metabolic cost
 the tongue can directly sense sweetness; shows how important sweet foods are
to our evolution
o saltiness is one of the few other tastes that the tongue can sense directly
 other animals like salt too
 herbivores will travel great distances to eat salt, because plants are not rich in
sodium
 if you deprive a rodent of salt, they will drink nothing but high-salinity solutions
that would normally be disgusting
 humans ingest way more sodium than they should
 Health Canada says we should ingest around 1,500 mg of salt
 we should never exceed 2,300 mg
 but most adults consume over 3,400 mg every day
 this is bad, because excess sodium consumption can lead to
hypertension, high blood pressure, and other life-threatening conditions
 in addition to preferring certain foods, humans can also learn to avoid foods that cause sickness
o this type of avoidance only takes one trial
 if a food makes you sick once, you will probably never want to eat it again
o even the smell of sickening foods can trigger nausea
 if a food is very odorous, you will avoid other odorous foods, even if the smells
themselves are different
o dietary neophobia: animals (and some humans) tend to avoid foods they have never
eaten before
 elimination is another vital motivation, but we won't talk about it much
o there are three types of elimination - urination, defecation, and vomiting - but we will
only discuss vomiting
 the area postrema, which can be found at the base of the brain, controls the
vomiting reflex
 other parts of the brain also control the vomiting reflex, but the area
postrema is special…
 it does not have a blood-brain barrier, so it can sample the blood
without putting other parts of the brain at risk
 the area postrema contains receptors which detect certain toxins
 if you eat something poisonous, the area postrema will detect the poison and
trigger your vomiting reflex
 the area postrema only causes vomiting from dietary toxins; it does has nothing
to do with vomiting out of disgust
o disgust is a primary emotion, stereotyped across cultures
 it is also stereotyped across age; emerges early in infancy, does not really
change as people grow up
 even across species, disgust is universally triggered by feces, death, and odors of
decay

31. Part 6: Pain, Fear, and Comfort
 thermoregulation, the process of regulating temperature, is one of our basic motivators
o animals seek comfort in reaction to extreme heat and cold
o the more excessively hot or cold you become, the more you seek comfort; eventually,
it's all you can think about
 temperature is sensed by cutaneous receptors (receptors in the skin), as well as temperature-
sensitive neurons in the hypothalamus
o both sources of information converge in the hypothalamus
o the posterior nucleus of the hypothalamus motivates us to conserve heat, while the
preoptic nucleus motivates us to avoid heat
 both interact with the anterior pituitary through hormone actions
 the anterior pituitary secretes hormones that affect the rest of the body
o the posterior nucleus secretes thyroid-releasing hormone and sends it to the pituitary
 the pituitary then secretes thyroid hormones
 increases sympathetic nervous system activation
 shivering, goose bumps (piloerection), narrowing of the blood vessels
(vasoconstriction, especially when cold is related blood loss)
o the preoptic nucleus inhibits thyroid hormone secretion
 prevents the hypothalamus from releasing thyroid-releasing hormone
 deactivates sympathetic nervous system
 sweating, panting, thirst, vasodilation (dilates the blood vessels, especially in
the outer-skin to facilitate heat-loss)
 there are also behavioral responses to excess heat and cold
o we search for comfortable places
o we wear warm clothes or breathable t-shirts
 pain is another huge motivator
o pain disincentivizes maladaptive or self-injurious behaviors
o if you didn't have pain, there would be no reason to avoid hurting yourself
o when rest and recovery are needed, pain keeps you from being active and exacerbating
your condition
o in some cases, it is actually better to be active while injured (for example, while being
attacked)
 if this is the case, the body temporarily inhibits pain, a phenomenon called
analgesia
 the physiology and pathways of pain:
o nociceptors: receptors for pain
 they are free nerve endings, which means they don't need a chemical to be
activated
 great at responding to thermal and mechanical stimuli
 there are two types:
 C fibers are not myelinated, which means they send signals slowly (slow,
dull, aching pain)
 A-delta fibres are myelinated, so they send signals quickly (sharp, fast,
prickling pain)

32.  both fibres synapse in the dorsal horn of the spinal cord before ascending to the
brain
 there are three major pathways to the brain: spinothalamic,
spinoreticular, and spinomesencephalic
 the spinothalamic path leads to the thalamus, where pain is integrated
with emotional responses and general consciousness (you become
aware of your pain)
 if you electrically stimulate this tract, it causes pain; if you lesion
this tract, it inhibits pain
 the sensation of pain is specific to this tract; if you stimulate or
lesion the dorsal horn or thalamus, it does not affect pain
 the spinoreticular path goes through the reticular system, where pain
stimulates general arousal (shock or alertness), before completing in the
thalamus
 the spinomesencephalic tract leads to the midbrain, which is involved in
pretty much every motivation and emotion, before going to the
amygdala
 interacts with the hypothalamus, potentially causing analgesia
 two types of chemicals are involved in analgesia
o endorphins, such as ACTH (which promotes cortisol production) and beta-endorphin,
are released by the pituitary during stress
o enkephalins are small peptides derived from a variety of materials; they are
concentrated in the periaqueductal gray (PAG) and the dorsal horn of the spinal cord
o both hormones bind to endorphin receptors
o endorphin receptors are concentrated the PAG and dorsal horn, where enkephalins are
produced
o endorphins, enkephalins, and opioids (like heroin and morphine) interact with these
receptors to produce analgesia
o endorphins bind to receptors in the PAG, sending signals through descending tracts
from the brain to the spinal cord, where pain messages are inhibited by inhibitory
interneurons
 the pathways that move up from the spinal cord to the brain are called
ascending tracts
 the inhibitory interneurons can act on either the ascending tracts or the C and
A-delta fibres themselves
 inhibitory interneurons release GABA, which prevents the firing of neurons
~~~~~~~~~~~~~~~~~~~~~~~~~~~
 the perception of pain is very subjective
o pain perception is not always proportional to injury
 a paper cut or stubbed toe may elicit a stronger response than a broken leg
o perception of pain is partially determined by the body's analgesia-to-pain ratio
 a stubbed toe isn't that painful, but there's little to no analgesia
o the visual analog scale is a scale of subjective pain perception from 1-10, based on facial
expressions
 it's useful, but it doesn't objectively measure pain
o different people can have very different experiences of pain, and the same person can
experience the same painful event differently depending on a variety of factors

33.  while pain is a response to actual damage in the body, fear is the anticipation that damage
might occur
o if we didn't fear pain or injury, we would get injured and die more often
o we are most afraid of ancestral dangers (snakes, predators, spiders, heights, etc.), even
though these dangers are no longer threatening to us
 the visual cliff experiment:
 position a baby on a solid surface, half of which is transparent glass
 if the baby walks near this glass, it thinks it's crawling along a cliff
 the baby will not crawl over the glass, even when beckoned by its
mother
 the more active and self-locomotive a baby is, the better its depth-
perception, the less likely it is to crawl across the glass
 shows that our fear of heights is partially innate
 cars, guns, and knives, however, are not often feared, even though they are
much more dangerous
 this is a good example of evolutionary lag
 although fear is constrained by innate processes, it can be conditioned, sometimes in one trial
o a single traumatic event can cause lifelong phobias and post-traumatic stress
 in one case study, a woman had a traumatic experience at the dentist's office;
from then, on merely sitting in a chair that resembled her dentist’s chair was
enough to trigger panic attacks
o a series of subtraumatic events can also lead to fear conditioning
 if a mailman is frequently attacked or barked at by dogs, they can be gradually
conditioned to fear them
o fear can also be socially transmitted
 if a young monkey observes an adult monkey behaving fearfully towards an
object, the young monkey will also be fearful
 fear responses themselves are mostly innate
o learning new responses to fearful stimuli is difficult, sometimes impossible
o innate responses may interfere with learning new fear responses
 when rats receive inescapable electric shocks, they develop a fear response
(usually freezing or running away)
 it takes quite some time to train these rats to avoid the shock by pressing a lever
beforehand
o examples of innate responses:
 species-specific defense reactions:
 fleeing
 fighting
 freezing
 other reactions
 hiding
 burying, burrowing themselves or fearful objects
 perspiration
 spontaneous urination or defecation
 vocalizations, like crying and screaming
o it is very hard to learn not to do these things
~~~~~~~~~~~~~
 fear responses are triggered by the sympathetic nervous system

34. o unlike the PSNS, whose ganglia are located close to the organ tissues they affect, the
SNS's ganglia are chained together
o when one ganglion in the sympathetic chain ganglia fires, it propagates to every other
ganglion in the chain, thus affecting every organ in the SNS
 when something scares you, you need to kick every part of your body into high
gear at once
 parasympathetic functions do not demand whole-body reactions, so the PSNS
doesn't need a chain of close-together ganglia
o the SNS triggers these fear responses by way of noradrenaline:
 pupil dilation
 allows you to take in more of your surroundings
 increases respiratory and heart rate
 prepares you to run away from danger
 also prepares you for a fight
 inhibits stomach and intestinal function, preventing digestion
 the blood that normally goes to the stomach is directed instead to other
body parts, as described below
 inhibits production of saliva (but not salivary enzymes) in the salivary gland
 this dries the inside of your mouth, allowing you to take in more air
during a single breath
 inhibits the production of tears in the lacrimal glands
 decreases sexual response
 you don't want blood rushing into the wrong organs
 increases perspiration
 to cool you down while running/fighting
 liberates energy from stored fat and glucose
 fighting and fleeing both require a lot of energy
 prepares for defense reactions (fight/flight) in other ways
 increases blood pressure by constricting the blood vessels (vasoconstriction)
that supply the skin, digestive tract, brain, and smooth muscle
 by constricting blood vessels, the SNS directs blood away from these
parts of the body
 during fight/flight reactions, the skin, digestive tract, brain, and smooth
muscle do not need blood as much as the skeletal muscles
 speaking of which, the SNS also dilates the skeletal muscles' blood
vessels, giving them the oxygen, energy, and nutrients needed to carry
the body away from danger
 SNS vasoconstriction, like most other SNS functions is caused by
noradrenaline and adrenaline
 there are multiple adrenergic receptors throughout the body,
each of which respond to both noradrenaline and adrenaline
 most of the time, these receptors exhibit the same response to
adrenaline and noradrenaline
 there are two adrenergic receptors that control
vasoconstriction: alpha 1 adrenergic receptors, and beta 2
adrenergic receptors

35.  alpha 1 adrenergic receptors constrict blood vessels in
the skin, digestive tract, brain, and smooth muscle
when exposed to adrenaline or noradrenaline
 beta 2 adrenergic receptors dilate arteries in the
skeletal muscles when exposed to adrenaline or
noradrenaline
 increases function of the adrenal medulla, which produces catecholamines like
noradrenaline
 prolongs the fight/flight response
 if it weren't for the SNS's stimulation of the adrenal medulla, the
fight/flight reaction would end really quickly, because noradrenaline is a
monoamine neurotransmitter
o catecholamines in the central nervous system, like dopamine and norepinephrine, are
also elevated following exposure to aversive or fearful stimuli
 promotes general arousal and awareness
 the increase in dopamine levels does not necessarily indicate a reward
mechanism
o during extreme or intense fear, these reactions are observed:
 loss of peripheral vision
 piloerection (goose bumps)
 this has an evolutionary context
 when humans had fur, goose bumps raised their hackles, making them
seem larger and more imposing
 shaking
 caused by over-activation of the skeletal muscles
 spontaneous urination and defecation
 could disgust predators, making them less likely to eat us
o the amygdala is also part of the fear response
 like the hypothalamus, the amygdala is a complex organ containing many nuclei
 it tells us whether to approach or avoid stimuli by conditioning anger and fear
 electrical stimulation of the amygdala's lateral areas can induce fear, defensive
behaviors, and alertness
 electrical stimulation of other areas can diminish fear and defensive behaviors
 human fMRI studies have shown that the amygdala activates upon viewing
fearful facial expressions
 there are two amygdala nuclei to consider
 the basolateral nucleus integrates stimuli and sensory memories with
feelings of fear
 helps us learn to be afraid of things
 allows to recall whether stimuli should be avoided
 every kind of stimulus, from visual to olfactory, can be
conditioned with a fear response
 the cortical nucleus is responsible for our sense of smell and
pheromone processing
 it receives input from the olfactory bulb and olfactory cortex
 the centromedial nucleus is involved in the arousal of emotions
 the amygdala is connected to many other parts of the brain, including…

36.  the hypothalamus, which controls the SNS and therefore the fear
response
 the thalamic reticular nucleus, which integrates sensory input with
physical reflexes
 the trigeminal and facial nuclei, which processes facial expressions
 as stated earlier, the amygdala affects our perception of
emotional faces
 the ventral tegmental area, locus coeruleus, and laterodorsal
tegmental nucleus, each of which produce a specific catecholamine
 the ventral tegmental area contains dopamine cell bodies
 the locus coeruleus synthesizes norepinephrine
 the laterodorsal tegmental nucleus activates the production of
epinephrine
 Urbach-Weithe disease: a disease that gradually atrophies the amygdala
 people with this disease are generally less afraid of things
 they have no special memory for traumatic events
 they also have difficulty recognizing fear in others, which relates to the
amygdala's relationship with the trigeminal and facial nuclei
o pheromones may be involved in fear for certain species
 mice and cattle, for example, will avoid areas where other members of their
species have been afraid
 when studying pheromones of fear, you have to account for a variety of
confounding variables
 mice spontaneously defecate when afraid, so other mice may be
avoiding places out of disgust rather than fear
 humans are instinctively frightened by things that move slowly towards us
o even stimuli that wouldn't normally be fearful can cause a slight, general sense of
unease
Part 7: Reproduction (with special thanks to an
anonymous contributor)
 animals compete for all sorts of things (resources, territory, social status, etc.)
 all of these things help us survive and reproduce, but the act of reproduction itself drives
competition more than anything
 because males and females have different reproductive goals, they compete with each-other as
much as they compete with themselves
o in mammals, there are pretty clear differences between the sexes
 males…
 have a constant supply of sperm
 usually invest less in their offspring
 they do not have to carry children to term, nor do they always
nurture their young
 never become infertile
 may seek multiple mates

37.  compete for females
 females…
 have a select number of eggs, only one of which is available at a time
 generally invest more in offspring
 will eventually become infertile, assuming they live long enough
 usually only mate with one (or two) males
 allow males to compete for them
 in some species, females compete for males
o as stated earlier, these differences sometimes lead to competition between males and
females
 females have to be cautious and selective while mating, while males want to
mate with as many females as possible
 if a female mates in the wrong conditions (wrong season, wrong
location, wrong amount of food, etc.), it could hurt the offspring
 they usually want to mate with the best male they can find, to the
exclusion of other males
 what females define as the "best male" varies between species
 males cannot always be certain that their children are their own (the degree to
which a male is certain of his paternity is called paternity confidence)
 to prevent uncertainty of paternity, many males will guard their mates
from other males
 sometimes, if a male realizes he has been cuckolded, he will kill the
offspring to preserve resources and restart the female's reproductive
cycle
 key terms related to mating and bonding:
o K-selection: a species has a small amount of offspring and invests in them quite a bit
 results in higher offspring survivability
 maintains a constant population
 humans and humpback whales are both K-selectionists
o r-selection: a species has lots of offspring and doesn't invest much in any of them
 very brief juvenile period in these species
 low offspring survivability
 creates large population changes
 mice and fruit flies are both r-selectionists
o monogamy: one female and one male are paired together
 monogamy is good for less dominant males who have trouble controlling
resources and territory, because monogamy gives them a higher chance of
mating with at least one female
 the best males can only take one female, which leaves the other
females for less successful males
 leads to female-female competition for access to males (occurs in humans, bald
eagles, and some other mammals)
 serial monogamy: several brief monogamous partnerships in succession
 advantages of monogamous male-female bonding:
 there is less risk of catching diseases, because you only ever have sex
with one person
 biparental (two-parent) care increases offspring success and
survivability

38.  females also benefit; they receive assistance with raising kids, and they
are protected by male partners
 disadvantages of monogamous male-female bonding:
 excludes all other mating opportunities; what if someone better comes
along?
 worse, what if your partner is infertile?
 and what if your partner deceives you? what if they mate with someone
else on the side?
 this is especially threatening to males, who have a lot to lose
from cuckoldry
 males may abandon, neglect, or abuse the cuckolder male's
children, as well as the cuckolding female herself
o polygamy: males and females both engage in multiple pairings
 in polygamous societies, males compete more often than females, because
females are the choosier sex
 diseases are rampant due to frequent sexual activity, and paternity isn't always
certain
 males will not bond with or care for young, because the children might not be
theirs
 females take care of each-others' children to make up for male absence
o polygyny: males have multiple pairings with several females, sometimes in a harem
 polygynous societies reward dominant males at the exclusion of lower status
males
 male-male competition is very intense in these societies
 polygyny a good arrangement for lower-status females, who are usually
guaranteed access to high-status males
 there is some interfemale competition as to who gets the most resources from
their male
o polyandry: females have multiple pairings with several males
 hive insects often live in polyandrous societies
 polyandry is rare in mammalian species
 when polyandry occurs, it is usually motivated by kinship; two or more brothers
share a single wife
 low-status females lose out in this arrangement, because males only have to
choose the best females
 there is some intermale competition as to who gets to impregnate the female
first
o promiscuity: no exclusive romantic partnerships within a species
 this is true in animals like mice
 human reproductive strategies:
o we are a K-selected species
o biparental care is common but not universal; lots of single mothers and fathers
o serial monogamy is prevalent in western culture, but other cultures use other mating
strategies
 animals depend on certain stimuli to trigger mating behavior
o visual stimuli, tactile stimuli, and olfactory stimuli all play a role
o many species rely on visual stimuli, but the most obvious example is blood-engorged
genitalia, especially in female chimpanzees

39. o other species, like moths, respond to the olfactory stimulation of pheromones
o tactile (touch) stimuli are also important
 female mice will arch their backs in a way that makes it easier for males to
mount them; this behavior is seen in other species as well
 some snails pierce each-other with love darts (yes, that is the actual term)
during mating dances
 around the end of the dart, there is a mucous that contains hormones
which open the snails' copulatory orifices, increasing the chance of
mating success
 sexual behavior in males:
o mounting: climbing atop the female to begin sexual intercourse
o intromission: the act of inserting the penis into a vagina
o ejaculation: the ejection of semen from the penis
 sexual physiology in males:
o the SNS and the PSNS both play a role in sexual behavior
 the SNS is responsible for ejaculation, while the PSNS causes erections
 the SNS innervates the genitals from the lumbar nerves, while the PSNS
innervates genitals from the sacral nerves
o hormones are also a factor
 men go through a daily cycle of high-to-low testosterone levels
 testosterone levels peak at about 8 AM and decrease throughout the
day, only to spike back up the following morning
 sexually active men of all ages go through this cycle, but younger males
have higher levels of testosterone overall than do older males
 this cycle is dependent on hormone transmission within the hypothalamo-
pituitary-adrenal axis (HPA axis)
 the hypothalamus secretes gonadotropin releasing hormone (GnRH)…
 which causes the anterior pituitary to release follicle-stimulating
hormone (FSH) and luteinizing hormone (LH)…
 which cause the testicles to secrete testosterone…
 which sends negative feedback to the hypothalamus and pituitary,
telling them to stop producing hormones…
 and when testosterone levels get low enough, the cycle starts again
 daily variance of testosterone has no effect on sexual response in humans
 if you inject testosterone into a man, they will probably not become
more sexually active
 castration reduces male sexual response over time
 if a male animal frequently has sex, it will take longer to stop
performing sexual behaviors
 hormones from the adrenal glands can also affect post-castration sexual
behavior
 Phoenix performed this experiment in 1974:
 they castrated rhesus monkeys and injected them with
dihydrotestosterone (DHT)
 control group consisted of uncastrated rhesus monkeys
 over time, with help from DHT injections, sexual behavior
increased in the castrated monkeys
 "intact" monkeys were unaffected by the injections

40.  shows that sexual behavior can be triggered even in castrated
males
 male sexual arousal is also facilitated by minor increases in arousal, stress, and
catecholamine hormones
 of course, extreme stress diminishes sexual arousal, as does fatigue
 sexual behavior in females:
o lubrication of and blood flow to the genitals
o lordosis: arching the back in such a way as to accommodate a mounting male
o proceptivity: behavior that demonstrates the female's desire to mate, like presenting
genitals to a male
o receptivity: behavior that allows or encourages males to mate
 if a female is unreceptive, she will try to escape from mounting males
 sexual physiology in females:
o the HPA axis is also involved in female reproduction
 the hypothalamus secretes GnRH…
 which causes the anterior pituitary to secrete FSH and LH…
 which trigger ovulation
o unlike males, who thrive under small amounts of stress, female sexual behavior is
completely inhibited by stress hormones
 if a woman is stressed out enough, it could terminate her pregnancy
 this process also makes use of the HPA axis
 the hypothalamus secretes corticotropin-releasing hormone (CRH)…
 which causes the anterior pituitary to secrete adrenocorticotropic
hormone (ACTH)…
 which causes the adrenal cortices to innervate the kidneys…
 which then secrete cortisol…
 which inhibits ovarian activity
o why are women so strongly affected by stress in this way?
 because women, unlike men, need a safe and stress-free environment in which
to raise their offspring
 if a woman experiences even a little bit of stress, it means that her environment
is not ideal for raising a child, so there is no point in wasting the energy required
to reproduce
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ovaries and adrenal glands both release estrogen and progesterone, but the adrenal glands are
a much greater determinant of sexual interest than the ovaries
o women who have had their adrenals removed are much less interested in sex
o this is only true for adult human women, not rodents
 even if you remove a female mouse's adrenals, she still shows signs of sexual
interest
 but if you remove her ovaries, sexual behavior goes away completely
o why do the adrenals matter so much?
 because androgens stimulate sexual behavior more than any other chemicals,
including estrogen and progesterone
 ovaries produce androgens too, but not as much as the adrenal cortex
 menstrual cycle in human women:
o the menstrual cycle is divided into two phases: the follicular phase and the luteal phase

41. o during the follicular phase, the HPA axis releases FSH and LH, starting the development
of an ovarian follicle, otherwise known as an egg cell
 the follicle contains a single oocyte (an immature egg) that grows over the
course of the follicular phase
 at the end of the follicular phase, the egg is released from the follicle into the
fallopian tubes; the release of this egg is called ovulation, and it marks the shift
from the follicular phase to the luteal phase
 the egg’s release coincides with a sharp spike in LH
o during the luteal phase, the now egg-less follicle folds in on itself, becoming a corpus
luteum
 the corpus luteum releases estrogen and progesterone, causing the
endometrium, the inner mucous membrane of the uterus, to grow
 if the woman becomes impregnated, the endometrium will act as a cushion for
the zygote
 at the end of the luteal phase, if the woman has not been impregnated, the
corpus luteum dissolves into scar tissue, and the endometrium sheds its excess
lining
o the endometrium has its own cycle, called the uterine cycle, which coincides with the
menstrual cycle
 the uterine cycle starts with the proliferative phase, when the endometrium
begins to proliferate (grow through cell multiplication) in response to estrogen
 during the secretory phase, the endometrium responds to progesterone
released by the corpus luteum and proliferates into a much larger secretory
lining
 this secretory lining is filled with essential nutrients
 at the end of the luteal phase, menses begins, and the endometrium sheds its
secretory lining
 menses is triggered by a sudden dip in progesterone, caused by the
dissolving of the corpus luteum
 what happens to a woman's emotions over the course of her menstrual cycle?
o Jones et al performed this study in 2005:
 subjects were pre-menopausal women
 divided based on menstrual phase
 rated male facial averages based on attractiveness, perceived masculinity, and
apparent health
 women late in their cycles expressed a preference for healthy faces
 women in the follicular phase had a weaker preference for health but a
greater preference for masculinity than mid luteal phase
 theory as to why this is the case:
 progesterone released during the luteal phase could reduce preference
for masculinity
 ovulation has already occurred, and the woman probably mated during
that time, so she doesn't need to be on the lookout for masculine men
 what she really needs is a healthy mate who can take care of her
without making her sick or endangering her child
o Conway et al performed this study in 2007:
 again, subjects were pre-menopausal women
 divided into two conditions: high progesterone and low progesterone

42.  subjects rated female facial averages
 each facial average exhibited one of the following emotions: fear, disgust, and
happiness
 some of the facial averages were looking at the camera, as though
making eye contact, while others looked off to the side
 this was the only difference between facial averages within expressions
 so, in total, there were six facial averages: fear with eye contact, fear
without eye contact, disgust with, disgust without, happiness with,
happiness without
 facial averages were rated based on the intensity of the emotional expression
 again, the only real difference between facial averages was emotion and
whether they were making eye contact
 both high and low progesterone conditions rated happy with and happy without
as equally intense
 the high condition thought fear and disgust were more intense while looking off
to the side
 reasons why this may be the case:
 eye contact vs looking off to the side: the difference between someone
being disgusted by you or being disgusted by something in the
environment
 women with high progesterone are likely to have been impregnated, so
they have to pay attention to environmental cues of fearful or
disgusting things
 it's more important to pay attention to the environment than to oneself
 the physiology of pregnancy and fertility:
o the greater the duration of copulation, the better the chance of fertilization
 sexual arousal removes barriers to sperm; for example, the cervix opens slightly
 oxytocin is released during orgasm, causing uterine contractions that help move
sperm past the cervix
o pregnancy is a huge investment of resources that causes all sorts of physical, emotional,
and behavioral changes
 as stated earlier, stress can cause pregnancy loss; the body will abort the child
to conserve resources that help the woman survive
o the physiology of pregnancy
 during pregnancy, there is no menstrual/estrus cycle
 progesterone levels are high throughout pregnancy
 when progesterone levels fall, it signals the end of the pregnancy
 the child is born shortly thereafter
 during parturition (the act of childbirth), oxytocin is released, causing uterine
contractions that push the baby out
 oxytocin pathway:
 when the fetus's head pushes against the cervix, it sends nerve impulses
to the brain
 the this causes the pituitary gland to secrete oxytocin, which is carried
to the uterus through the bloodstream
 oxytocin stimulates uterine contractions and pushes the fetus through
the cervix
o after birth…

43.  usually, women are very happy after childbirth
 10-15% of women go through post-partum depression, but no one is sure why
 social situations can contribute to stress and depression after childbirth
 for example, if the baby is isn't heavy enough, and the mother is
constantly asked how heavy their child is, it can cause stress
 it can also put a lot of stress on the mother if the baby has a birth defect
o when nursing, oxytocin and prolactin are released from the pituitary
 oxytocin causes feelings of parental love and stimulates bonding between
mother and child
 the following experiment demonstrates the importance of oxytocin to mother-
child bonding:
 when a female mouse is presented with a litter that is not her own, she
will not take care of them
 …unless she receives a dose of oxytocin
 prolactin is released from the pituitary when the baby sucks on his/her mother's
nipple
 prolactin then travels to the mammary gland and stimulates milk
production
 brain differences between men and women
o there is a gene on the Y chromosome that causes development of testicles in utero; this
same gene is responsible for most of the differences between male and female brains
o the sexually dimorphic nucleus (SDN) of the preoptic area (POA) of the hypothalamus,
specifically the third interstitial nucleus of the anterior hypothalamus (INAH3),
determines sexual behavior in men, but not women
 the POA has actually been shown to inhibit female sexual behavior, but research
is ongoing
 the SDN-POA is much larger in males than in females
 the entire brain is larger in males than in females, but not by much, so
we aren't sure if it makes a difference
 for the SDN-POA, though, size definitely matters
 if a man's POA is lesioned, he will never exhibit sexual responses again
 hypothalamic chemicals affect the pituitary, remember? if you kill the
hypothalamus, you kill GnRH and therefore sexual behavior
 electric stimulation of the POA increases sexual response in rodents
 lesioning of both amygdalae causes hypersexuality, among other effects, in cats
(we learned this through experimentation) and humans (learned through
observation, not experimentation)
 cats will attempt to mount other animals, including animals currently
engaged in sexual behavior
o in female brains, the ventromedial hypothalamus (VMH) determines sexual behavior
 when estrogen is applied to the VMH, it induces sexual receptivity in female
rodents
 the septum also controls sexual behavior in women; stimulating the septum
decreases sexual receptivity, while lesioning the septum increases sexual
receptivity
 we're not totally sure why this happens
 homosexuality
o several species exhibit homosexual behavior

44.  fruit flies have a gene that lets them distinguish between males and females; if
you remove this gene, they will mount both genders
 because 65% of albatrosses are female, sometimes females form pair bonds
 one of the females mates with a male from a heterosexual pair bond
o there is more research on male homosexuality than female homosexuality, because
there are more homosexual men than women
 generally speaking, anything that can be applied to gay men can also be applied
to lesbians
o evolutionary theory of homosexuality:
 some scientists think that homosexuality is a by-product of polygyny, where
some men are unable to reproduce with women
 this group of men who cannot reproduce are instead driven to help their more
successful kin
 they forage for food and take care of children
 because homosexual men cannot reproduce already, they are perfect for this
role
 the genes responsible for homosexuality get passed down thanks to kin
selection
o but for homosexuality to be an evolved trait, it must have some genetic component
 Bailey and Pillard performed this study in 1991:
 they analyzed homosexuality in monozygotic twins, dizygotic twins, and
adoptive brothers
 if you have one homosexual monozygotic twin, you are also likely to be
homosexual
 more likely than dizygotic twins, and MUCH more likely than
adoptive brothers
 this implies that homosexuality is partly genetic
 Damer performed this study in 1993:
 looked at family trees for homosexual men
 brothers had a comparatively high chance of being homosexual, as did
maternal male relatives
 basically, if you are homosexual, anyone on your mother's side of the
family is likely to be homosexual as well
 indicates that the X chromosome is possibly involved in homosexuality,
specifically the genetic sequence called Xq28
 indeed, homosexual men showed higher activation of this gene than
heterosexual men
 we cannot be sure, but there is growing evidence supporting this view
~~~~~~~~~~~~~~~~~~~~~~~~~~`
 if homosexuality is an X-linked trait, what happens to women with the gene?
o Iemmola and Ciani performed this study in 2014
 the researchers went around Italy asking homosexual and heterosexual males
how many children were born in their immediate and extended family
 how many children do your aunts, uncles, grandparents, etc. have?
 homosexual men had greater fecundity (more children born) on their mother's
side, but not their father's side
 females with this gene have greater fecundity, thus increasing the fitness
benefits of homosexuality

45.  homosexuality could simply be a by-product of this fecundity-increasing gene
 how do hormones affect physiology and sexuality at birth?
o in mice, testosterone levels at birth determine the size of the rodent's SDN-POA
 if you castrate a male and give him estrogen and progesterone, his SDN-POA will
become small and feminized, and he will take on female sexual receptivity
 if you give a female testosterone, her SDN-POA becomes masculinized; the
mouse becomes more aggressive, more dominant, and will sometimes show
mounting behavior
o so how do hormones affect development in the womb?
 vom Saal performed this study in 1989
 examined the litters of pregnant mice
 looked at the gender and position of each pup in the litter
 some pups are adjacent to two male mice (2M), some are
adjacent to two female mice (0M), and some are adjacent to
one of each
 females compared the amount of estradiol and testosterone in females
surrounded by males with that of females surrounded by other females
 2M females were exposed to more estradiol and testosterone than 0M
females
 these hormones affected behavior later in life
 2M females exhibited less lordosis behavior and acted much
more aggressively, sometimes attacking other females
 males were less attracted to 2M females; when given a choice
between entering a cage with a 2M and a 0M, they usually
chose the 0M
 this shows that hormones in utero can affect development and behavior
 overall, 2M males had more testosterone than 2F males, who had more
testosterone than 2M females, who had more testosterone than 2F
females
 2M males had larger SDN-POA's than 2F males, whose SDN-POA's were
larger than those of 2M females, whose SDN-POA's were larger than
those of 2F females
 some more information on homosexuality:
o adult heterosexual and homosexual males have the same amount of androgens and
estrogens
 however, the INAH3 is smaller in homosexual males and male-to-female
transgendered individuals
 basically, in utero hormones are no indication of whether someone will turn out
to be homosexual
o the more sons your mother has had, the more likely you are to turn out homosexual
 male fetuses express the H-Y antigen; without this antigen, they would not be
male
 if you graft this antigen onto females, their body rejects it as if it were a
disease
 the mother's immune system also resists the H-Y antigen
 if the antigen gets into the blood, the mother's body will produce
antibodies that may cross the placental barrier and feminize the male
fetus's brain by killing its H-Y antigens

46.  the more male children a woman has, the better her body gets at fighting H-Y
antigens, and the more feminine her male children are likely to become
 we don't know for sure if this happens, because it's difficult to research
 it would be unethical to induce a mother's immune system to attack her
child
o psychosocial factors of homosexuality
 if, when young, you are rejected romantically by the opposite sex, you may be
inclined to pursue relationships with your own sex
 if you enjoy relationships with people of the same sex, you are conditioned to
become homosexual
 again, it would be hard to test this theory
Part 8: Arousal and Stress
 arousal: general awareness, awake-ness, attention, and shock
o it's a very nebulous term; lots of psychologists think it shouldn't be used
o many psychologists think we should just call it stress, because a lot of the physical
underpinnings of stress overlap with arousal
 there are three types of arousal:
o underarousal: associated with negative affect (bad mood), poor performance on most
tasks, and a desire to become more aroused
o moderate arousal: associated with high performance and a positive affect (good mood);
this is the ideal
o overarousal: impairs performance, associated with a desire to become less aroused
through relaxation; not a pleasant experience
o these three classifications follow a bell curve from most desired to least desired
 over and underarousal are not ideal
 underarousal leads to under-reactivity, while overarousal leads to excessive
stress
 dopaminergic pathways and the reticular formation are responsible for general arousal and
attention
o the reticular formation is part of the reticular activating system
o the reticular formation is involved in general wakefulness
 boredom is an unpleasant sensation associated with underarousal and a lack of excitement
o when bored, you are motivated to do something exciting
o boredom causes irritability, poor performance, decreased heart rate and blood
pressure, and the inability to pay attention
o Heron performed this study in 1957
 invited subjects into his lab under the pretense of a sensory deprivation
experiment

47.  subjects were placed in a dark room, blindfolded, surrounded by white noise,
while wearing a full-body suit to prevent tactile stimulation
 they subjects lied on a bed without moving
 they could only get up to eat and use the bathroom
 the longer subjects stayed in the sensory deprivation chamber, the more money
they received
 there was massive variation in how long subjects stayed in the chamber
 some subjects stayed in for a long time, others left very soon
 when subjects left the room, they were asked to perform a variety of tasks, all
of which they performed poorly on
 the subjects could not concentrate on anything; their minds wandered
frequently
 most subjects were also quite irritable
 shows that boredom leads to poor performance and underarousal
o this is why Ritalin improves concentration: by increasing arousal, it prevents boredom
 overarousal can sometimes take the form of surprise
o surprise is a primary emotion with its own set of reflexes
 the Moro reflex in human infants is a good example
o lots of stereotyped facial expressions: mouth opening, eyes agape, etc.
 animals like dogs and horses, who depend on their hearing, perk their ears
when surprised
o surprise comes from a violation of expectancy; when something unexpected happens,
we feel surprised
o stereotyped across all ages and species
 stress is the psychophysiological consequence of any event that challenges an organism's ability
to cope with their environment
o stressors: any stimuli that disrupt an organism's homeostasis, requiring adaptation or
readjustment
o general adaptation syndrome: the stress response, divided into three stages
 note: general adaptation syndrome is not a disorder despite the ominous-
sounding name
 acute stress (emergency reaction): a sudden bout of stress caused by a
shocking or traumatic event
 during acute stress, the SNS activates, and catecholamine hormones
(epinephrine and norepinephrine) are released from the adrenal
medulla
 catecholamine neurotransmitters (dopamine and
norepinephrine) are also cycled through synapses in the CNS
more often
 norepinephrine is associated with attention and sensory
processing in times of stress
 dopamine starts a chain-reaction in the HPA axis, eventually
leading to the production of cortisol
 cortisol has little to do with acute stress, however; it's all about
the SNS
 here's how the HPA produces cortisol:
 dopamine activates the hypothalamus…
 which releases corticotropin-releasing factor (CRF)…

48.  which causes the anterior pituitary to secrete
adrenocorticotropic hormone (ACTH)…
 which causes the adrenal cortex to produce cortisol…
 which sends a negative feedback signal to the hypothalamus
and anterior pituitary, inhibiting production of CRF and ACTH
 this negative feedback loop affects your circadian rhythm
 cortisol levels are at their highest in the morning, before
you wake up, and lowest at night, when you go to sleep
 it's the same as testosterone
 other functions of cortisol:
 liberates energy stored in fat and glucose
 converts amino acids and fatty acids to glucose
 stimulates your appetite
 facilitates the release of adrenaline from adrenal glands
 suppresses growth hormone and the immune system
 the anterior pituitary also releases beta-endorphin, which is involved in
the reticular activating system
 rebound (resting phase): a slow, segmented deactivation of the SNS in
conjunction with reactivation of the PSNS
 different parts of the SNS deactivate at different times and in
different orders, depending on what happens after the stressful
event
 heart rate, blood pressure, and digestion all return to normal
 acetylcholine is active in both the SNS and PSNS during this
phase
 examples of acute stressors
 novelty: the sudden appearance of something new
 loss of social status and resources
 failure to perform; not being as good at something as one would expect,
or performing worse than your peers
 loss of control in life or in one's environment
 certain cognitive challenges
 receiving too small of a reward
 social isolation, depending on the species
 chronic stress (resistance phase): a long-lasting stress response caused by
prolonged difficulties in coping
 characterized by activation of the HPA axis and increased levels of
monoamine neurotransmitters in the CNS
 in times of extreme stress, the hypothalamus and pituitary are so
overwhelmed by cortisol that the negative feedback loop stops working
 several hormones affect the body in unexpected ways during chronic
stress
 ACTH normally acts solely on the adrenal cortex, but it can also
affect the brain, stimulating catecholamine activity
 corticotropin-releasing factor also has anxiogenic effects
(causes anxiety), possibly because it influences the
hypothalamus, which is involved in nearly every emotion and
motivation

49.  chronic stress can affect circadian rhythm and the immune
system; many people report flu-like symptoms and feelings of
exhaustion during chronic stress
 corticosteroids in the PNS increase your metabolism, decrease
your immune response, and inhibit physical
growth/reproduction
 corticosteroids in the CNS bind selectively in the limbic system
to the hypothalamus, amygdala, hippocampus, and septum
 moderate levels of central corticosteroids can inhibit
the production of monoamine oxidase (MAO), which
breaks down serotonin, dopamine, and norepinephrine
 the inhibition of MAO and subsequent increase
in serotonergic, dopaminergic, and
noradrenergic activity is associated with
increased affect
 this is why MAO inhibitors used to be a popular
antidepressant
 so, in moderate amounts, central
corticosteroids are good for you
 …but in the high levels achieved during chronic stress,
corticosteroids can cause clinical depression
 symptoms of chronic stress:
 suppression of immune response, growth hormone, and the
reproductive system, all of which are functions of cortisol
 reduced central monoamine activity
 elevated blood pressure
 negative affect
 damage to the hippocampus
 weight gain in midsection
 shorter life span
 stress shortens telomeres, the strings of DNA on the
end of your chromosomes
 when telomeres get too short, the body is no longer
able to reproduce cells
 telomeres naturally shorten with time, but stress
accelerates this process
 Epel conducted this study in 2004
 looked at two different groups of mothers:
mothers with healthy children, and mothers of
chronically ill children
 it is safe to assume that mothers with
healthy children have lower stress
levels than mothers with ill children
 examined mothers' self-rating of perceived
stress after having children
 also measured the chronicity of caregiving
(number of years since childbirth)

50.  compared the results of these questions to the
mothers' telomere length
 chronicity of caregiving correlated with shorter
telomeres for mothers with chronically ill
children
 perceived stress rating also correlated with
shorter telomeres
 there was a statistically significant
difference in perceived stress levels
between healthy mothers and ill
mothers
 there was also a difference in telomere
length
 these results suggest that chronic stress can, in
fact, shorten your lifespan
 examples of chronic stressors:
 severe loss of control in life
 failure to cope over a long period of time
 social subordination: falling down the social hierarchy or having to
submit to someone above you
 exhaustion: a complete mental and physical collapse caused by chronic stress
 the time it takes a person to reach exhaustion varies, as does their
symptomatology
 usually when people get stressed out, they aren't sure when
they will enter exhaustion
 exhaustion can cause psychopathology, physical disease, and death
 humans are pretty weird when it comes to stress
o for example, by pressing the snooze button, you are cancelling out a sudden rush of
cortisol caused by the shock of the alarm clock, only to be woken up again five minutes
later
o a lot of things people accept as being normal, like commuting to work, are actually
terrible for us because of the stress they cause
 if you move into the city you're working in, stress levels go down, even though it
isn't economically advantageous
 your life at work doesn't change, but your life outside of work improves
o in summary, stress is extremely advantageous from an evolutionary standpoint… unless
you put yourself in stressful situations for no good reason
 as stated earlier, stress inhibits reproduction
o females are more strongly affected than males
o pregnancy and nurturance are, on average, far more costly for females than for males
o stress inhibits ovulation, menstrual cycling, and the continuation of pregnancy
o females need a good, stress-free environment in which to raise children, so if they're
stressed out, they can't reproduce
 other dimensions of arousal that we won't discuss in detail
o blood sugar and nutritional status can affect both general arousal and stress response
 low blood sugar produces the same responses as underarousal
o deviations in the levels of cortical neurotransmitters like GABA can really throw things
out of balance

51. o just as cortisol affects the circadian rhythm, so too does the circadian rhythm affect
stress
 your hormones do not know what to do when you stay up late
 the more nights you are awake in a row, the more your body will adjust, until
sleepless nights eventually become the norm
o rest and fatigue affect stress both long and short term
o your general health affects stress and arousal
 still, if you get sick, your body probably won't release cortisol, because it inhibits
the immune system
 some people, called thrill seekers, enjoy overarousal
o thrill seeking behavior appears to be linked to monoamine activity, both catecholamines
and indoleamines
o causes the activation of adrenal hormones
o males who do not have partners, kids, or other such responsibilities are most likely to
seek risks
 coping: successfully dealing with a situation, usually with a bit of help from stress, followed by a
return to normal levels of arousal
o the ability of each individual to cope varies, which is why different people hit exhaustion
at different points
o the better you are at coping, the longer it takes for someone to become exhausted by
stress
o when you fail to cope - when you cannot solve the problem that causes stress -
heightened arousal persists, causing chronic stress and eventually exhaustion
 exhaustion refers to more than just being tired
 it is characterized by excessive adrenocortical activity (overproduction of
cortisol), depletion of neurotransmitters and reduction of synaptic firing,
idiosyncratic weaknesses (the weaknesses that appear in people when they are
stressed out), and illness, physical or mental
 physiological symptoms of exhaustion:
 heart failure and stroke
 ulcers
 if you shock a mouse repeatedly with no option to escape, the
mouse will be more likely to develop ulcers than a mouse who
can escape or control the shocks, who in turn have more ulcers
than mice who are never shocked
 decreased immunity
 tumor growth
 that is to say, if you already have a tumor, its growth is
facilitated by stress
 as far as we know, stress alone does not cause tumors
 depression and suicide
 post-traumatic stress disorder is a form of chronic stress caused by traumatic events
o short term effects, immediately after the stressful event:
 shock
 terror
 delirium
 sleeplessness
 sensory disturbances (like hallucinations)

52.  coma
o long term effects
 paranoia
 delusions
 night terrors
 emotional lability: involuntary displays of extreme emotion
 depression
 sweating
 enuresis: inability to control urination
 headaches
 sensorimotor difficulties
Part 9: Anger, Hate, and Aggression
 there are seven forms of aggression:
o predatory aggression is directed at other species with the intent of eating them
 it is the aggression that a predator feels towards its prey
 example: rats killing mice
 rats attack mice with a stereotyped bite to the neck that kills instantly
 the biting behavior does not have to be learned; it has a genetic
component
 when you put a mouse in a cage with a rat, even when they can't
contact each-other, the mouse's corticosterone levels become
extremely high, indicating mice naturally see rats as a threat
o intermale aggression occurs within species between males competing for the same
resources, territory, or females
 interfemale aggression is less common but works the same way
 example: seals, kangaroos, bears, zebras, giraffes… basically any species where
males have limited access to females
o territorial aggression protects an individual's territory
 chases away trespassers
 marks the boundaries of territory
 can occur within and between species
 the act of taking someone else's territory is also territorial aggression
 example: a dog barking at the mail man for intruding on its marked territory
o defensive aggression occurs when an animal must defend itself
 if the animal is being attacked, or if it feels vulnerable, it may become aggressive
 animals may also try to defend kin, resources, or territory
 it is the aggression that prey feels towards predators
o maternal aggression is felt by mothers in defence of their nest or offspring
 paternal aggression is less well-studied, but it works the same way
 K-selected mothers exhibit maternal aggression more often than r-selected
mothers
 usually always defensive
o irritable aggression is induced by frustration or pain

53.  example: mice will fight each-other when housed together and subjected to
repeated foot-shocks
 as the duration of the foot-shock increases, so too does the probability
of fighting
 the longer the foot-shock, the more frustrated they become
o instrumental aggression is learned and developed through conditioning
 this form of aggression usually occurs in pursuit of a reward but could also be
motivated by escape
 instrumental aggression, like most forms of aggression, can overlap with other
forms
 example: humans in hate groups are conditioned to behave aggressively
towards certain other groups of people.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 dominance: behavior performed with the goal of controlling resources and ruling the social
hierarchy
o dominance comes from competitive interactions, many of which are aggressive or
threatening
o most dominance-related interactions appear in the form of threat and appeasement,
with no actual violence taking place
 violence is metabolically costly
 if you get injured in the wild, you will probably die, so it's better to threaten
than to fight
o threat, an action that asserts dominance, comes in many forms:
 self-maximizing postures (making yourself appear larger)
 angry facial and vocal expressions, like barking
 sometimes piloerection, the raising of the hackles
o appeasement, an action that mitigates threatening behavior, is embodied in the
following ways:
 self-minimizing postures (making yourself appear smaller)
 withdrawal; shying away
 dogs will sometimes cower when barked at, even when humans are
barking
 displaying female sexual postures
 these sexual postures probably have nothing to do with actual sexual
desire
 males are not usually able to mate in times of extreme stress, so any
sexual postures displayed while under threat are probably just
appeasement
 some species-specific gestures
 wolves expose their necks when threatened
 this is a powerful gesture of appeasement, as the neck is one of
the most vulnerable parts of the body
 smiling is a form of appeasement in humans and apes
 infanticide: the killing of offspring
o can be performed by either males or females
o infanticide in males:
 males usually avoid killing their own offspring

54.  in most species, males do not expend resources taking care of their offspring, so
there's never a need to "recoup" the resources through infanticide
 so from a fitness standpoint, there is usually no good reason for a male to kill his
offspring
 there is a huge evolutionary benefit, however, to killing the offspring of other
males
 for example, female mice are unable and unwilling to reproduce while
taking care of offspring, but by killing the litter, a male can force the
female to start cycling again, giving them the chance to reproduce
o infanticide in females:
 infanticide occurs as a result of aggression directed towards their young
 if the female is low on resources and cannot gain support from other members
of their species, she will kill her children for her own survival
 females will also commit infanticide in times of stress, because stress is often a
sign that the environment is unsuitable for children
 if a female has too many offspring, or if the offspring are weak or defective, the
female may kill them
 females don't always actively kill their young; sometimes, they just abandon
them
 sex differences in aggression
o in many mammalian species, males are more aggressive than females
o this aggression can be observed in rough and tumble play, which is seen in humans,
dogs, cats, gorillas, and other animals
 this play can sometimes be indistinguishable from actual fighting; the only
difference is that no one comes to harm on purpose
o in adult humans, one of the best ways to measure differences in aggression is through
homicide rates
 up until age 14, males are as likely to be victims of homicide as females
 from that point on, however, males are much more likely to be killed by other
humans
 this could be a sign that men find themselves in aggressive situations more
often than females
 physiology of aggression
o perinatal and pubertal testosterone correlate with higher levels of aggression in many
species
 the more testosterone you are exposed to in-utero and during puberty, the
more aggressive you are likely to become
o castration reduces or eliminates intermale aggression in many species
o female mice injected with testosterone perinatally and throughout adulthood show
male levels of aggression
 these results are not seen in female mice injected only during adulthood or only
perinatally; you need both
 intermale aggression in various species:
o red deer
 unlike males of most species, red deer have many violent encounters
 physical violence is more common than nonviolent threat, which is a
rarity for reasons listed above

55.  however, this extreme violence is only displayed during a particular time of
year: mating season
 testosterone levels are at their highest in November, when females
enter estrus
 at other times of year, red deer are far less physically aggressive
 male red deer grow antlers at this time of year
 the bigger the antlers, the more likely a red deer is to win a fight
 antler size is mostly tied to genetics, but there is also a
nutritional component, so red deer with bad genes still have a
chance to win
 when mating season ends, red deer shed their antlers and put an end to
violent aggression
o house mice
 aggression in house mice occurs spontaneously: no learning required
 male house mice direct aggression towards other males
 if you place a female near two males, those males will probably fight to the
death, even if neither male has direct physical access to the female
 pheromones may be at work here
 females usually only show defensive aggression, often while protecting their
offspring
 stereotyped aggressive actions in house mice:
 tail rattling (shaking the tail quickly)
 biting at the flank and hindquarters, trying to render the other mouse
unable to move
 after a fight, mice experience certain chemical and behavioral changes:
 if a male house mouse wins a fight, they…
 become more aggressive
 become more assertive towards other mice
 become more sexually active
 they try to mate with more females, and the females
may be more receptive to their advances
 show higher levels of catecholamine activity
 dopamine is part of the reward circuit of the brain, so
high levels of dopamine post-fight encourage the
mouse to fight more often
 show higher levels of testosterone produced by gonads
 testosterone is directly implicated in aggressive
behavior in house mice
 show decreased activity in the adrenal cortex, reducing stress
 if a male house mouse loses a fight, they…
 become less aggressive, less assertive, and less sexually active
 show lower levels of catecholamine activity
 low levels of catecholamines are implicated in clinical
depression
 show lower levels of testosterone produced by gonads
 show increased activity in the adrenal cortex, causing stress
 so, in summary:
 mice who win fights are driven to fight more often

56.  mice who lose fights are driven to fight less often
o rhesus macaques
 rhesus macaques, like humans, are a highly social species with complex pecking
order
 monkeys with a stable, dominant position in the hierarchy show high levels of
testosterone
 monkeys with a stable, subordinate position show lower levels of testosterone
 if you take a dominant monkey and put him in a new group, his testosterone will
diminish, because he has to work his way up the hierarchy again
o humans
 in human males, the connection between testosterone and aggression is unclear
 you can have males with high aggression but low testosterone and males with
high testosterone but low aggression
 boys' testosterone levels increase during puberty, as does aggression, but the
two are not always related
 testosterone is probably more strongly related to social dominance than
outright aggression
 testosterone levels change based on social success and failure
 new army recruits show a substantial decline in testosterone levels,
similar to rhesus macaques who enter new social groups
 testosterone is also related to victory and failure
 testosterone levels drop when men fail medical licensing exams and go
up when a favored sports team wins
 testosterone levels also go down when a favored sports team loses
 the physiology of aggression:
o the hypothalamus is related to two types of aggressive attack:
 affective attack: the "Halloween cat" posture, where the animals screams,
arches its back, exposes its teeth, and undergoes piloerection
 induced in many animals, including cats, by stimulating the medial
hypothalamus
 not only will the cat perform the posture during medial hypothalamic
stimulation, it will also perform it in the presence of prey, like rat),
which usually never happens
 cats only make this posture while afraid or threatened, as when
they are approached by a dog or male cat
 there is no need for a cat to threaten a mouse
 quiet biting attack: searching for prey, pouncing on them, and biting their head
and neck without emotion
 exhibited in cats, rats, opossums, and monkeys
 induced by stimulating the lateral hypothalamus
 both of these attacks are very stereotyped and strongly connected to the
hypothalamus
o the amygdala - of which there are two, one on either side of the brain - have a complex
structure and location, making it hard to pin down their exact relationship with
aggression
 when stimulated, some parts of the amygdala trigger aggression and
threatening postures, while others reduce aggressive behavior

57.  the rabies virus, which is known for causing aggression, attacks the temporal
amygdala more than any other part of the brain
 rabies induces severe and unprovoked aggression
 animals that would usually never attack a human being will become
prone to bite when infected with rabies
 damage to the amygdala changes the way animals express emotion, but more
than that, it changes the way they interpret information
 animals with amygdalar damage often have trouble deciphering social
cues
 they may behave inappropriately or attack others without provocation
 in male cats, lesioning of the amygdala causes indiscriminate mounting
behavior
 10% of humans with temporal lobe epilepsy experience uncontrollable
outbursts of rage
 again, the amygdala is a complicated organ, so it's not as frequent as
100%
 tumors in this area can also induce rage behavior
 an ex-military man named Charles Whitman went on a 16-
person killing spree due to a pecan-sized tumor pushing up
against his amygdalar region
 prior to this, he was not characterized as violent or aggressive at
all
 in his suicide note, he requested that an autopsy be done,
because he felt like there was something inside him driving this
behavior
o catecholamines are very active in the brain during aggressive encounters in mice
 aggression in mice is focused on the limbic circuits of dopamine and
norepinephrine
 drugs like amphetamine, which activate catecholamine receptors, cause slight
increases in aggressiveness when taken at moderate doses
 high doses can cause brain damage, resulting in chronic aggression
o the prefrontal cortex regulates aggressive behavior
 this is one of the few things we know for sure about the prefrontal cortex
 electrical stimulation of the prefrontal cortex suppresses affective attack and
quiet biting attack, but not flight responses
 in other words, the prefrontal cortex shuts off the fight response, but
not the flight response
 this was observed in cats by Siegel et al in 1974, but we have reason to
believe that the prefrontal cortex does the same thing in humans
 Best et al performed this study in 2002
 preface: humans with damage to the prefrontal cortex display impulsive
aggressive behavior
 aggressive behavior appears much more often in people with
prefrontal cortex damage than in people with temporal lobe
epilepsy (10%)
 unsurprisingly, people with prefrontal cortex damage perform
poorly on tests that measure prefrontal cortex capability

58.  patients diagnosed with intermittent explosive disorder, not caused by
prefrontal cortex damage, also display impulsively aggressive behavior
 even though their prefrontal cortices aren't damaged, these
people perform poorly on tests that measure prefrontal cortex
capability
 it could be that people with stunted prefrontal cortex
development are more likely to behave aggressively
Part 10: Happiness, Sadness, and Coping
Strategies
 affect and emotions are subjective
o different people find different things funny, sad, etc.
o people express their emotions in different ways
o emotion is a social function
 we evolved our emotions not to gain a better understanding of ourselves, but to
communicate our feelings to others
 as a result, it is hard to objectively and quantifiably asses our own emotional
states
o positive affect (a visibly good mood) is usually elicited by gains and successes
o negative affect (a visibly bad mood) is usually elicited by loss and failure
 how do humans express their affect?
o we express affect through our faces, postures, energy levels, vocalizations, and
behaviors
o facial affect expressions: smiling, frowning, grimacing, etc.
 one would expect that people look at the mouth first when gauging someone's
facial expression
 instead, we first look at the eyes
 after checking the eyes, we look at the eyebrows, then the whole of the face
including the mouth
o postural affect expressions: walking upright (erect) or slumped, looking forwards or
down
o activation: are they energetic, or do they move and act slowly?
o vocal affect expressions: the contours of your voice move up during positive affect and
down during negative affect
o behavioral patterns: laughing, crying, etc.
 these behavioral patterns are connected to facial expressions, but many
behaviors are dissociated with the face
 non-facial expressions include shrugging one's shoulders or crossing one's arms
 basic affective states:
o smiling
 emerges early in development, usually the first few days, and occurs frequently
during mother-infant interactions

59.  crying is probably the earliest indicator of affect
 smiling could mean a few things:
 usually, smiles express happiness or joy
 smiling can also be influenced by conditioning
 babies and certain pets may learn to smile because it gives them
positive attention
 types of smiling:
 Duchenne smile: a genuine smile
 involves a lot of muscle activity in the face; the eyes wrinkle,
and the cheeks are pulled up
 it is easy to fake a smile, but hard to fake a Duchenne smile
 in a fake smile, there is not usually any eye wrinkling or cheek
raising
 a Duchenne smile activates emotional centers of the brain; a
fake smile only activates the motor cortex
o laughing
 laughter is observed in many other species, although it doesn't always sound
like a human laugh
 usually indicates a positive affect
 in humans, laughter emerges very early in infancy, usually within the first few
weeks
 involves a lot of the same facial muscle activations as smiling, but it also
activates other body parts, including the reticular formation, limbic system, and
caucal muscles
 people with damage to the reticular formation do not laugh the same
way that healthy individuals laugh
 in humans and in other species, laughing is social; other people can be amused,
appeased, or complemented by laughter
 laughter can also be used to diffuse aggression or lessen negative affect
 we often laugh in response to things we aren't comfortable with
 sometimes, laughter enhances negative affect in others, as when
laughing at someone who feels embarrassed
 hormones associated with laughter:
 cortisol, epinephrine, and growth hormone all decrease during laughter
 this lessens activity in the CNS
 laughter also improves certain immune factors
 in summary, laughter alleviates stress and improves your health
 smiling and laughing, like other basic affective expressions, occur in blind babies
and individuals
 this implies that they are innate, unlearned behaviors
 blind adults do not always know how to fake facial expressions, even
though they perform them instinctively
 Provine completed this study in 1992
 recruited about 120 subjects
 used a "laugh box" to play the sound of laughter in front of subjects
 recorded the behavior of subjects and had them rate their own affect
after listening to the laugh box

60.  the first time the laugh box was played, subjects usually laughed along
with it
 subjects almost always rated their own affect as being slightly
higher
 this improved affect could have either been caused by the laugh
box or the subjects' own laughter
 after listening to the laughter 10 times, subjects assumed a more
negative affect; they found the laughter annoying
o crying
 also occurs in many species, although we see it more often in humans than in
other animals
 stereotyped across all cultures and ages of development
 crying is the most prominent emotion displayed immediately after birth
 it ensures that the baby quickly enters the mother's arms
 if the baby does not enter the mother's arms right after birth, it affects
the mother-child bond
 crying after birth isn't always associated with negative affect;
sometimes, crying is caused by separation from the mother
 one major function for crying is to signal distress and request assistance
 there are many connotations associated with crying, most of them negative
 for example, an adult who cries a lot is thought of as immature or a
"crybaby"
o mourning
 a natural response to the death of a loved one
 goes beyond simple communication; this type of affect can have a lasting impact
on the person experiencing it
 mourning is associated with the following behaviors and emotions:
 waves of dysphoria, crying, etc.
 loss of initiative and hope
 some people experience depressive affect, but not usually clinical
depression
 mourning can persist for several months
 when someone of high reproductive potential dies, their loved ones mourn for a
longer period of time than they would if someone with low reproductive
potential had died
 what makes you sadder: a 15-year-old dying, or an 80-year-old dying?
 depression
o as stated earlier, clinical depression is not the same as depressive affect
 you can feel depressed without experiencing clinical depression
o clinical depression does not always express itself visually
 depressed individuals sometimes pretend to be happy
 sadness and depression are stigmatized in our society, so there is good reason
to fake happiness
o depression has several components
 affective: dysphoria, anxiety, slumped posture, lowered voice, sorrowful facial
expressions
 social: difficulties socializing, problems with rejection by others, withdrawal
from society

61.  cognitive: low self-esteem, feelings of helplessness, cognitive distortion
(depressed individuals do not interpret things the way normal people do)
 behavioral: lack of initiative and motivation, difficulty engaging with problems,
inactivity and malaise
 physiological: sleep and appetite disturbances, chronic HPA activation (relates
to cortisol and stress), abnormal circadian rhythm (many depressed individuals
sleep too often), serotonin disruptions
o in depressed individuals, cortisol levels stay high throughout the day
 chronic elevations of cortisol are a classic sign of enduring stress and coping
difficulty
 causes circadian rhythm disruption
 as stated in a previous lecture, chronic stress reduces hypothalamic-pituitary
control over cortisol, as the HPA axis's negative feedback loop disappears
o anaclitic depression: depression that occurs in children who are deprived from their
mother
 phases of anaclitic depression:
 phase one: initial protest
 crying, rejecting others, actively seeking the mother
 phase two: despair
 dysphoria, motor retardation, decreased response to
environment, low appetite, insomnia, agitation, hopelessness
 phase three: detachment
 self-centeredness, resisting new emotional bonds
 not all sufferers of anaclitic depression reach this stage
o childhood depression is less common than adult depression, but it follows many of the
same trends
 causes can include family stress, rejection from peers, social isolation, mourning
loss of parents or close family, or abuse
 cortisol levels are much higher in children during family instability
 depression is expressed through crying, inactivity, and sometimes rebellion
o Angelman syndrome, a disorder usually diagnosed in childhood, is sometimes thought
of as the "opposite" of depression
 the disorder is associated with a variety of physical and mental abnormalities,
from simple "behavioral uniqueness" to full mental retardation
 Angelman syndrome is unlike depression, in that it is physically evident
from birth
 children with this disorder almost never experience negative affect; they are
always laughing and smiling, and they have excitable personalities
 the abovementioned behavioral uniqueness is not enough; you also need the
physical and mental symptoms to be diagnosed with Angelman syndrome
 the physiology of affect
o monoamines like serotonin, dopamine, and norepinephrine are greatly influenced by
our coping status
 people who are able to cope with their environments show greater monoamine
activity
 people who cannot cope with their environments have lower monoamine
turnover
 foods and drugs that raise monoamine levels also improve mood

62.  foods/drugs that lower monoamine levels cause negative affect
 we know serotonin affects mood, but the connection isn't clear
 because affect is subjective and elusive, it's hard to connect any one
serotonergic pathway with mood
 we only know that serotonin affects mood because drugs that interact
with serotonin receptors (MDMA, LSD, DMT, etc.) have an influence on
affect
 people who take these drugs usually have an elevated mood
 many parts of the brain contain serotonergic receptors; it's hard to tell
which ones affect mood
 after all, there is no way to limit a drug to one section of the
serotonergic pathways
 MDMA also acts on noradrenergic receptors, so noradrenaline is implicated with
mood as well
 noradrenaline, like serotonin, cannot be restricted to one section of its
pathways, so we cannot be sure which noradrenergic parts of the brain
affect mood
 dopamine is less involved with mood itself and more involved with reward
mechanisms
 dopamine is associated with consumatory behaviors (eating, drinking,
sex, and other biological drives/addictive behaviors that lead to feelings
of reward)
 reward is caused by dopaminergic activity in nucleus accumbens
 dopaminergic reward causes positive affect
 satisfaction is a natural consequence of doing something you
want to do
 MDMA, amphetamines, and cocaine all interact with dopaminergic
receptors in the limbic system and nucleus accumbens
 all three of these drugs are highly addictive for this very reason
o indoleamines are associated with negative affect, rather than positive
 the pineal gland secretes melatonin in darkness, and melatonin suppresses most
other glands in your body, which causes a variety of physical changes
 melatonin is produced at the expense of serotonin, because serotonin and
melatonin are both synthesized from tryptophan
 tryptophan --> serotonin --> melatonin
 when given the choice between using tryptophan or serotonin to
synthesize melatonin, the body always chooses serotonin, because it
takes less metabolic effort
 some people experience depression-like symptoms during Winter
months, when the sky is darkest; these people have seasonal affective
disorder (SAD)
 the easiest treatment for SAD is moving to a tropical climate
 Russians used to stand in front of UV lights to promote vitamin
D production during winter months, but this was discovered to
cause melanoma
o anandamides are usually associated with hunger, but they also determine affect
 endogenous cannabinoid neurotransmitter is found in both the CNS and the
PNS, and is associated with elevated affect

63.  fun fact: "ananda" is Sanskrit for "delight"
o endorphins and dopamine have a similar relationship with affect
 endorphins are generally used by the body as an analgesic
 they also influence affect, but we're not sure how
 beta-endorphins are released from the pituitary during times of stress
 they affect receptors in the periaqueductal grey, but beyond that we
don't know much about their influence on affect
o monoamine oxidase (MAO) is an enzyme that breaks down monoamines
 it exists in the synapse between neurons; when neurotransmitters are released
into the synapse, MAO comes in to break them down
 when MOA is inhibited, monoamines remain in the synapse longer, promoting
positive affect
 MAO inhibitors used to be a popular treatment for depression, but not anymore
 today's antidepressants only target one or two monoamines, and
instead of preventing breakdown, they inhibit reuptake
 this way, only the most underrepresented monoamines are targeted
 there are three transporters responsible for monoamine reuptake:
 the serotonin transporter (SERT) is a membrane protein that binds to
serotonin and transports it back to the presynaptic neuron
 SERT genes are polymorphic among humans, meaning a
heterozygous genotype is expressed as a cross between
homozygous phenotypes
 human polymorphisms of SERT are related to the expression of
affect
 SERT activity is also affected by the environment through
epigenetics
 selective serotonin reuptake inhibitors (SSRI's) prevent
serotonin reuptake by blocking SERT
 the norepinephrine transporter (NET) is also a membrane protein that
binds to its titular monoamine, norepinephrine, and brings it back to the
presynaptic neuron
 selective norepinephrine reuptake inhibitors (SNRI's) work the
same way as SSRI's
 epigenetics can reduce the expression of NET, impairing
neuronal reuptake of norepinephrine
 this is implicated in panic disorder and postural
orthostatic tachycardia syndrome (POTS), which is
when a person experiences tachycardia while standing
up or sitting down
 the mechanism of POTS is unclear
 norepinephrine is heavily involved in the firing
of CNS neurons, so there could be excessive
adrenergic activations of receptors related to
the heart or back
 this shows how the expression of neurotransmitters and
their transporters can influence both physical and
mental disorders

64.  if you inhibit the wrong transporter, it can cause
severe side effects
 the dopamine transporter (DAT) is a membrane protein that binds to
dopamine and returns it to the presynaptic neuron
 selective dopamine reuptake inhibitors (SDRI's) are used to
inhibit this transporter
 suicide: a discrete act that leads to death
o suicide is well-documented internationally, because we keep records of people who
commit suicide
o suicide rates are not strongly affected by technological advancement; little variation is
seen across time
 suicide rates differ greatly between nations and societies
o although suicide rates stay the same with time, suicide methods change with the advent
of new technologies
 self-hanging used to be the most common method of suicide, even though it
was slow and painful
 the same is true fire, cutting, piercing, poisoning, jumping from heights,
drowning, and exposure to harsh elements
 modern suicide methods include gunshots, drug overdose, gassing, and
automobile collision
 these technologies may prompt impulsive suicide, where an individual suddenly
decides to kill themselves, but the actual rates of suicide do not change much
 in the past, if you wanted to kill yourself you had to commit to
something excruciating; nowadays, suicide is much faster and easier, so
it can be a spontaneous decision with little planning involved
 parasuicide: a sub-lethal, survived attempt at suicide
o these are not as well-documented, because we do not keep track of failed suicide
attempts
o sometimes a person who commits parasuicide meant to commit real suicide; other
times, they never intended to kill themselves
 committing parasuicide can have social benefits, like sympathy and attention
 people who attempt suicide once are not likely to ever successfully kill
themselves, although they may attempt parasuicide again
o parasuicide is meant as a signal of distress
 predictors of suicide:
o (note: predictors of suicide are not necessarily predictors of parasuicide)
o age and sex
 suicide occurs four times more often in males
 parasuicide occurs nine times more often in females
 suicide occurs more frequently in the elderly and the infirm
 parasuicide occurs most frequently between the ages of 20 and 40
 suicide is rare in children
 suicide becomes more common with age in both males and females
 suicide in women starts to increase around the age of five, plateauing
around the 20's with a slight peak at 45
 coincides with menopause
 suicide in men increases drastically at around 65 years of age
 these figures are similar in other cultures

65. o desperation and hopelessness
 these factors are related to most cases of suicide
 marks the difference between individuals who intended to commit suicide or
parasuicide
 suicidal individuals are often incapable of coping with present circumstances
and expect little to no improvement in the future
 parasuicidal individuals may also be incapable of coping, but they are more
likely to believe that things will improve
 suicidal individuals often believe that their lives have lost meaning
o social isolation
 this is commonly attributed to suicide in young individuals
 students who kill themselves are often very shy; they do not interact with their
peers beyond what is required of them, and they have little presence in the
classroom
o reproductive status
 reproductive status declines with age, while suicide increases with age
 this explains why suicide peaks in females around the time of menopause, when
women become infertile
 evolutionary context for suicide:
o a failure to preserve oneself is favored by natural selection when these conditions are
met:
 one must have low reproductive potential
 one must act as a burden on their kin
o so for suicide to be advantageous from a fitness perspective, one must…
 be unable, unlikely, or unwilling to reproduce
 feel like a drain on their friends' and family's resources
o people who commit suicide often feel as though they are a burden on friends and family
Chapter 11: Love and Attachment
 love and attachment are found all throughout the animal kingdom, even in non-mammals
o friendship, familial bonds, and pair-bonds are observed in many species
 some forms of love and attachment are unique to humans
o for example, many researchers believe that our conscious experience of "love" is not
found in other animals
 Harlow defines three types of attachment:
o mother-infant (or, as it is known now, caregiver-infant)
 the mother-infant bond is more well-researched than any other form of
caregiver-infant bonding
 we research this attachment from the individual perspectives of mother
and infant
 a mother experiences this bond very differently from her child,
and vice versa
 paternal bonding is also observed in humans, as are many other forms
of caregiving
 siblings, aunts, uncles, grandparents, and other extended family
members may share a caregiving bond with a child

66.  extended families are common among other species as well,
such as lions, wolves, orcas, and hyenas
 the infant's attachment to his/her mother is divided into several phases
 phase one
 begins within the first three months of life
 considered the pre-attachment period, because the infant is
not yet attached to his/her mother
 for some other species, like sheep, attachment begins
immediately after birth
 there is a critical time period where the infant
must identify a primary caregiver
 this sudden and complete attachment is
referred to as imprinting
 human infants do not imprint
 instead, they spend the first three months of
life looking for a suitable caregiver, most often
the mother
 the mother must have a stable, constant relationship
with the infant
 if the infant does not find a stable caregiver within the
first three months, it can cause cognitive issues later in
life
 behaviors associated with phase one: nursing, clinging to the
mother, desiring to be close, cooing and other vocalizations
towards the mother, making eye contact, and crying in the
mother's absence
 all of these behaviors encourage the mother to remain
close to her child
 phase two
 takes place between months three and five
 at this stage, the infant can discriminate faces
 he/she shows positive affect towards familiar faces and
anxiety towards unfamiliar faces
 overall, this stage is about solidifying the mother-infant
attachment
 caregiving, feeding, and removing discomforts (diaper
changing, etc.) all contribute to this attachment
 phase three
 takes place between months six and seven
 at this point, the infant is clearly attached to the mother
 they will often cling to her, crawl towards her, and
perform other mother-seeking behaviors
 the infant explores his/her environment in relation to the
mother
 they always keep an eye on their mother when moving
around the room
 without her, they become lost

67.  the infant shows anxiety when separated from the mother and
placed in the care of strangers
 "strangers" could refer to anyone who isn't the mother,
including siblings and the father
 separation anxiety is different from other forms of
anxiety; it is implicated in several developmental issues
 phase four begins after 12 months
 the infant starts to form attachments with other caregivers,
including the father, siblings, extended family, and even
babysitters
 at this stage, the mother can potentially be replaced with
another caregiver
 for example, if the mother returns to work, and a
babysitter starts taking care of the infant during the day
- the infant may form a primary attachment with this
other caregiver
 the mother's attachment to the infant is very different
 in animals that have a high chance of performing infanticide (mice, for
example), the mother usually abandons her children before she starts
nursing
 this is advantageous, because nursing is resource-intensive, and
you don't want to waste those resources on an unfit pup
 when the mother starts nursing, she becomes attached to the
pup and is much less likely to commit infanticide
 as stated earlier, humans do not imprint
 however, skin-to-skin contact immediately after birth is
associated with positive attachment later in life
 there may be a critical period for skin-to-skin contact,
even though there is no critical period for attachment
as a whole
 research is ongoing
 other forms of progressive meshing (attachment-promoting
behaviors from the mother's perspective) include mutual eye
gaze, smiling, and "baby-play"
 are human nurturing behaviors found in other species?
 Lingle and Riede conducted this study in 2014:
 they studied female deer from two different
species: white-tail deer and mule deer
 the researchers placed speakers in the deer's
natural habitats
 speakers played a variety of infant vocalizations
from several species
 female white-tail deer were subjected
to vocalizations from both species, as
were female mule deer
 other vocalizations came from seals,
kittens, humans, and bats

68.  these vocalizations were re-
pitched to fit the deer's range
of hearing
 female deer from both species responded to
infant vocalizations from every species
 whenever a vocalization was played,
female deer would run towards the
speaker and look for an infant in
distress
 this shows that infant vocalizations are
analogous among several species
 hormones and maternal behavior:
 the menstrual cycle (or estrous cycle in other species) is
suspended during pregnancy, birth, and lactation
 progesterone levels are high throughout pregnancy, but they
decline immediately before childbirth
 oxytocin is released during childbirth to produce uterine
contractions and promote bonding between mother and child
 prolactin produces milk, while oxytocin facilitates the ejection
of milk from the nipple
 in lab rats, experienced mothers show maternal behavior much
more readily than "virgin" mothers, despite their similar
hormone levels
 when prolactin is injected into the brain of a virgin rat,
she becomes as nurturing as an experienced mother
 one would expect, then, that prolactin alone is
responsible for nurturance, but this is not the case
 virgin females who receive blood transfusions from
parturient mothers (who have very recently given birth)
also show increased nurturing behavior
 this shows that maternal behavior can be induced
through blood signals as well as hormones
 the medial and dorsal preoptic areas of the hypothalamus are critically
involved in maternal behavior in rats
 sensory inputs associated with childbirth (vaginal pain, etc.) are
sent to the dorsal preoptic area (POA) and the ventral bed
nucleus (VBN) of the striaterminalis
 the POA and the VBN relay this information to a wide variety of
areas, including the medial hypothalamus (MH), the ventral
tegmental area (VTA), the periaqueductal gray (PAG), the
habenula (HAB), and the septal area (S)
 the MH is involved in several motivations and emotions
 the VTA releases dopamine throughout the limbic
system
 the PAG is responsible for analgesia, which could ease
the pain of childbirth

69.  the HAB is involved in a variety of functions, including
pain processing, reproductive behavior, and stress
responses
 the S is associated with reward mechanisms
 overall, we aren’t sure exactly how these parts of the brain
respond to the POA and VBN, but it is safe to assume that they
assist childbirth
 the paternal bond is less reliable and more variable than the maternal
bond, even in species with biparental care
 in some species, however, the male is entirely responsible for
childcare, as is the case for stickleback fish
 males may take care of children through resources rather than
direct nurturance
 paternity confidence is an issue in many species, including
humans
 if a father is uncertain of his child's paternity, he may
not develop a strong bond
 the father's role in childcare may increase as the child gets older
 it's not until phase four that the child develops an
attachment to the father
 low levels of paternal care usually lead to problems later in life
 adolescent males without paternal care are more
aggressive and have difficulty socializing
 adolescent girls without paternal care often have low
self-esteem and an inaccurate idea of what to expect
from relationships with men
o peer-peer (or sibling-sibling)
 sibling-sibling bonds:
 siblings often compete for resources, so it may seem strange that they
even have a bond
 inter-sibling competition is especially common in the wild,
where mothers have to abandon their children to conserve
resources
 siblings often compete for maternal affection; jealousy is
observed from a young age
 inter-sibling aggression is also common, though it rarely leads to
injury
 however, siblings have a high coefficient of relatedness (0.5), so it
makes sense for them to have a relationship
 siblings may be your first playmates, depending on age differences
 humans are more likely to confide in their siblings than any other
person
 overall, siblings can be both friends and rivals, usually at the same time
 peer-peer bonds:
 as children grow, they become more independent from their families,
and peer-peer bonds become more common
 human children usually show interest in peers of the same age and sex
 peer-peer bonds come with several benefits:

70.  they give the child experience in social interactions
 they help the child learn to communicate
 peers often share helpful information
 sometimes, this information can help children develop
more quickly; children usually tell their friends when
they're doing something weird or inappropriate
 children acquire skills by playing with their peers
 peers form lasting alliances throughout development
o heterosexual (also applies to homosexual pair-bonding)
 begins with passionate love
 cognitive aspects of passionate love:
 lovers are constantly preoccupied by thoughts of the other
person
 they form idealized images of each-other in their heads
 emotional aspects:
 lovers are sexually attracted to one-another
 polarization of affect: things are either going really well or
really poorly
 they long for reciprocation of their feelings
 autonomic signs of physiological arousal are all there
 behavioral aspects:
 gazing, studying one-another
 seeking physical closeness
 courting/flirting behaviors
 sexting: a portmanteau of "sex" and "texting;" the practice of
electronically sending sexually explicit images or messages from one
person to another
 sexting is a common behavior among adolescents in love
 Temple et al performed this study in 2012
 wanted to learn how sexting contributes to the
formation of adolescent relationships
 took a sample of over 1000 high school students and
asked them questions about sexting
 have you ever sent a sext
 have you ever asked for a sext
 have you ever been asked for a sext
 do requests for sexts make you uncomfortable
 about 30% of high school students have sent sexts, with
little difference between males and females
 males ask for sexts more often than females
 females are asked for sexts more often than males
 females are less comfortable with being asked for sexts
than males
 if a student has ever sent a sext, asked for a sext, or
been asked for a sext, they are more likely to have
dated and had sex than students who answered "no" to
every question above

71.  when doing research on adolescent sexual
behavior, scientists could probably just ask
them whether they've ever sent a sext
 the researchers conclude that sexting is probably a
normal part of sexual development facilitated by
modern technology
 sexting teens are not "at risk" of anything
 companionate love begins when people have been in a close relationship for a
long time
 cognitive:
 members of the relationship are comfortable with intimacy
 they are willing to disclose personal information to each-other
 members have knowledge of each-others' strengths and
weaknesses
 they have long-term expectations of each-other
 emotional:
 not as big of an emotional rollercoaster as passionate love
 stability and trust are important
 there is potential for betrayal
 behavior:
 gaze is still common
 physical proximity is still sought after
 sexual behavior is common
 lovers communicate efficiently without speaking
 married couples are often used in research of companionate love
 in 2014, Francis and Mailon published a survey of over 3000
ever-married individuals in the US
 ever-married, meaning that individuals were married at
some point after 2008, though not necessarily during
the study
 the survey presented a lot of useful data, but it wasn't
very well-visualized
 later in 2014, Olson visualized Franics's and Mailon's data:
 the more time couples have spent together before
marriage, the less likely they are to divorce
 higher annual household income leads to lower chance
of divorce
 couples who go to church often are less likely to get
divorced than couples who never go to church
 couples who never go to church are less likely to get
divorced than couples who occasionally go to church
 partners who consider the wealth of their significant
other important are more likely to get divorced
 partners who consider physical appearance important
are much more likely to get divorced
 the more people attend the wedding, the less likely the
couple is to get divorced

72.  the less money you spend on your wedding, the less
likely you are to get divorced
 couples who go on a honeymoon are less likely to get
divorced
 could help relieve the stress of getting married
 couples who go on honeymoons are usually
wealthy, so there could be some crossover
 keep in mind, correlation does not equal causation
 physiology of sexual attachment:
 mating is very important to the development of attachment
 oxytocin is released during mating, which may condition lovers to
associate attachment with positive affect
 female prairie voles usually only chose a partner after mating,
but if they receive a dose of oxytocin in their CNS, they will
chose a partner without having mated
 drugs that block oxytocin do not effect mating, but they do
prevent partner preference
 oxytocin and vasopressin dynamics in the basal forebrain and septum
could influence romantic attachment
 the septum is involved in female sexual behavior
 when viewing photos of romantic partners, the anterior cingulate
cortex becomes more active than when looking at photos of friends
 this part of the brain is also involved in error processing,
although the two probably aren't related
 the posterior cingulate gyrus and amygdala become less active
when viewing photos of romantic partners
 a lot of these suggestions come from studies on animal sexual behavior
 the HPA axis can induce feelings of attachment and bonding…
 …which is strange, because when you engage in positive social
bonds, HPA activity decreases
 HPA activity increases, however, while engaging in negative
social bonds
 it can be stressful, interacting with people you don't like
 some romantic bonds involve jealousy
 there is a difference between envy and jealousy
 envy: wanting something you don't have
 jealousy: the fear that someone will take something you have
 the "something," in this case, is your romantic partner
 cognitive aspects of sexual jealousy in adults: shock, confusion,
suspicion, obsessive thinking
 emotional aspects: mix of primary and secondary emotions, including
anger, fear, despair, sadness, depression, anxiety, shame, and
embarrassment
 behavioral aspects: seeking information about partner, withdrawing
from them, plotting revenge, behaving aggressively
 adult humans show sexual dimorphism in jealousy:
 men are more concerned with sexual infidelity, while women
are more concerned with emotional infidelity

73.  the male preoccupation with sexual infidelity could come from
paternity uncertainty
 emotional infidelity means a lower inclination to share
resources, so it makes sense for women to be afraid of this
Part 12: Motivation to Learn
 in chapter three, we discussed the cognitive mechanism of learning
 in this chapter, we will discuss the drive to learn itself
 most animals explore new environments
o food, water, and shelter must be found
o potential dangers must be recognized
o the costs of any potential dangers must be weighed against the benefits of food, water,
and shelter
 individual members of any species weigh these costs and balances very
differently
 some people might think it's worth it to live near a lion's den; other
people don't
 the drive to explore is genetic; some individuals are naturally more willing to
explore than others
o an animal's success in exploration is determined by their ability to learn
 if you cannot remember where to find food, water, and shelter, you will have to
look for them more often, which will expose you to potential dangers
 the better you are at learning, the better you are at anticipating dangerous
situations
 animals prepare themselves for exploration and fighting through play
o play is observed in many mammalian species, including primates, marine mammals,
ungulates, and rodents
o play is most commonly observed in K-selected species, but it's hard to know for sure
which species play, because play is hard to define
 vague definition of play: inefficient behavior with no immediate, direct benefits
or clear goals
 this definition can be applied to lots of other behaviors
 scientists often think of play as behavior that provides new skills
 play behaviors often teach animals to fight
 play in rats usually involves pinning the other rat down, for
example
o play, like all other behaviors, has adaptive value
 for a behavior to evolve, its benefits must outweigh its costs
 costs of play:
 expends energy
 risks injury
 could attract the attention of predators if play is loud
 benefits of play:
 strengthens muscles
 facilitates social learning, competition, emotional expression

74.  helps the animal acquire skills, like hunting and fighting
 overall, the benefits seem to outweigh the costs
 in humans, however, play doesn't always result in the acquisition of new skills
 many humans engage in role-play or fantasy play
 this type of play may improve socialization, even though it
doesn't provide any new skills
o how is play expressed?
 rhesus monkeys have a "play face" that they show before engaging in aggressive
rough-and-tumble play
 signals to the other monkey that their actions are not intended to cause harm
 play in rhesus monkeys helps them learn posturing, wrestling, chasing, and
avoidance behaviors that will serve them well as adults
 many primates use tools to play, humans in particular
o the physiology of play
 the ventromedial hypothalamus is involved in play
 lesions to the ventromedial hypothalamus reduce play behavior, as will
larger lesions in the hippocampus, amygdala, cerebellum, and lateral
hypothalamus
 it is hard to say which of these parts are specifically involved in play and
which are only tangentially related
 removal of the neocortex reduces play behavior
 types of simple learning:
o habituation: repeated exposure to a stimulus reduces response to that stimulus
o sensitization: repeated exposure to a stimulus increases response to that stimulus
 classical conditioning: one stimulus becomes associated with another when both stimuli are
presented at the same time
 instrumental conditioning: a behavior is reinforced or extinguished through the presentation or
removal of certain stimuli following the behavior
o reinforcement: the consequence of a behavior causes it to increase in frequency
o punishment: the consequence of a behavior causes it to decrease in frequency
 if you put electrodes in a rat's brain - anywhere in the limbic system - and give them a mild
shock, the rat will do everything they can to continue this shock
o this is called electrical brain stimulation (EBS), and it is observed in most mammals
 cats, primates, and some humans have all shown a similar response to EBS
o if a rat only gets EBS'd in one part of the cage, the rat will spend most of their time in
that part of the cage, hoping to get shocked again
o if a rat gets EBS'd while doing work, they will work more often
 rats will push a lever thousands of times per hour just to get electrocuted once
o EBS is so engrossing, the rats will sometimes forget to eat or drink
o however, EBS-seeking behavior is very easily extinguished
 if the rat goes long enough without getting shocked, it will stop seeking the
shock and never start again (unless it gets shocked one more time)
 a rat who was EBS'd the previous day will wake up with no desire to be EBS'd
again
o the physiology of EBS reinforcement:
 produces a lot of activity in the lateral hypothalamus, around the region
traversed by the medial forebrain bundle (MFB), which is involved in every
monoamine circuit

75.  hard to nail down a specific part of the brain responsible
 dopamine, a monoamine neurotransmitter, originates in the ventral tegmental
area, moves through the MFB, and ends up in the nucleus accumbens (NAcc)
 if you administer dopamine to the MFB, it triggers the reward
mechanism
 if you administer anti-dopamine drugs to the NAcc, it blocks the reward
mechanism
 consummatory behaviors are associated with increased dopamine activity in the
NAcc
 dopamine circuits are clearly involved in reward, but there may be more
to it than just dopamine by itself
 memories of traumatic or exciting events are more intense and durable than memories of other,
more neutral or boring events
o why? because hormones associated with stress (ACTH, cortisol, and adrenaline) can also
enhance memory
 again, there are three stress-related hormones implicated in emotional memory:
adrenocorticotropic hormone (ACTH), adrenaline, and cortisol
o cortisol
 the hippocampus is strongly associated with memory, as is the amygdala, which
can be found on the tail end of the hippocampus
 there is some neural communication between the amygdala and
hippocampus
 both the hippocampus and amygdala contain glucocorticoid receptors to which
cortisol can bind
 during the emergency stress response, cortisol binds to these receptors,
facilitating memory consolidation
 sustained activation of these receptors can lead to atrophy of dendrites
and connections in the hippocampus and amygdala
 this is why chronic stress causes memory deficiency
o ACTH
 ACTH causes the adrenal cortices to produce cortisol, so naturally ACTH is
implicated in the consolidation of traumatic memories
 but for ACTH to stimulate the adrenal cortices, it must first be released through
activation of the HPA axis
 is this process fast enough to affect one's memory of a traumatic event as it
takes place?
 yes, actually, it is
 ACTH facilitates two types of cortisol production
 short-term cortisol production:
 takes place over several minutes
 stimulates the transportation of cholesterol into mitochondria
 the P450scc mitochondrial enzyme synthesizes cholesterol into
cortisol
 long-term cortisol production:
 takes place over several hours
 the P450scc enzyme doesn't last forever; it burns out eventually
 in the long-term, ACTH stimulates the coding of more
steroidogenic enzymes like P450scc

76.  in summary: ACTH does facilitate memory, but only through cortisol, and the
HPA axis is fast enough to affect memory
o adrenaline
 unlike cortisol, adrenaline is too large to cross the blood brain barrier
 two hypotheses as to how adrenaline affects memory formation:
 glucose hypothesis
 adrenaline frees the body's stores of energy, including glucose
 glucose crosses the blood brain barrier
 remember how the brain is the most glucose-intensive
organ in the body?
 in stressful situations, adrenaline releases large amounts of
glucose, much of which goes to the brain
 when the brain is full of energy, it is better at consolidating
memory
 peripheral receptors and amygdala (hypothesis)
 adrenaline stimulates the vagal nerve, which signals the nucleus
of the solitary tract in the medulla oblongata
 the nucleus contains noradrenaline/norepinephrine
neurons
 these norepinephrine neurons project to the
basolateral amygdala, which can enhance memory by
communicating with the hippocampus through neural
connections
 other forms of learning:
o types of reinforcers in instrumental conditioning:
 a primary reinforcer is something that naturally reinforces behavior
 includes all appetitive stimuli, like food, water, sex, or increased comfort
 if you put a primary reinforcer in front of a mouse or a baby, they will
instantly recognize the stimulus as something desirable
 a conditioned reinforcer is a neutral or non-natural stimulus which, through
conditioning, gains the capacity to affect behavior
 a mouse or baby will not recognize these stimuli unless they are
consistently paired with primary reinforcers
 money and good grades are both conditioned reinforcers, because we
have been conditioned to associate them with appetitive stimuli
o vicarious learning: learning through imitation, modeling, or contagion
 there is virtually no difference between "imitation" and "modeling"
 "contagion" could refer to behaviors we have no control over, like yawning, but
it's not a very good distinction
 Bandura showed that many behaviors are acquired through observation
 children who watch adults play with a novel toy will later imitate that
adult's behavior
 if adults played aggressively with the toy, children would also play
aggressively
 these children did more than just imitate their adult models; they
invented new aggressive behaviors that the adults did not perform
 if the toy was replaced with a person, the children would attack the
human being as though he or she were a toy

77. o vicarious reinforcement and punishment: if you watch someone's behavior being
reinforced or punished, you will be conditioned in the same way
 the effects of vicarious reinforcement and punishment can be as strong as those
of direct reinforcement and punishment
 there are also vicarious emotional responses; if you watch someone express
strong emotions, especially violent or romantic feelings, you may show the
same emotional responses yourself
o intrinsic vs extrinsic controls
 extrinsic rewards and punishers are externally imposed
 many extrinsic rewards and punishers are given to us by society
 for example, if you stay awake during a boring class because you need
the grade, you are succumbing to extrinsic controls
 intrinsic rewards and punishers are natural consequences of behavior
 intrinsic rewards often come from inside your body
 for example, the dopamine rush caused by eating fast food is an
intrinsic control
o incentive is different from reinforcement
 reinforcement and punishment have direct consequences that eventually lead
to a change in behavior
 incentive and disincentive are stimuli that affect behavior without direct
consequences
 for humans, the promise of reward and punishment is enough to
condition behavior, even if we have never actually been shown the
reward or punishment
 wealth is an incentive; you don't have to experience wealth to
play the lottery
 jail is a disincentive; you don't have to be arrested to obey the
law
 only occurs in humans and certain primates
Part 13: Conflicts Among Motives
 motivations often conflict with one another
 there are three types of conflicts among motivations:
o approach-approach: an organism wants to approach two equally desirable things, but
can only pick one
 the organism might take some time to make the decision; they will often
hesitate or go back and forth
 if a mouse is put in a maze and is forced to choose between peanut butter and a
banana, they will do this
 you can measure the amount of hesitation or the number of times they changed
their mind to see how hard of a decision it was
o approach-avoidance: a stimulus attracts and repels an organism at the same time; an
organism cannot obtain a positive stimulus without also exposing themselves to a
negative stimulus

78.  the closer the organism gets to the stimulus, the more hesitant and skittish they
become
 they may get close to the stimulus, then back away quickly
 if a mouse is electrified every time it collects food, it will show these behaviors;
you can measure the time it takes for them to get food
 in bats…
 vampire bats will sometimes regurgitate blood into a starving bat's
mouth; the more blood you give, the more likely you are to receive
blood in return
 is it better to give up food in hopes of reciprocation or keep
food to not starve?
 female big brown bats start hibernating before males
 males who haven't gotten the chance to mate will impregnate
sleeping females, but only if they have energy to spare before
hibernation
 is it better to mate with as many females as possible or
conserve energy over the winter
o avoidance-avoidance: the organism is presented with two equally aversive stimuli but
can only avoid one
 the organism hesitates or freezes, then approaches one stimulus, retracts
toward the other, and repeats for as long as it takes to make the decision
 a human example of avoidance-avoidance would be if the only way to escape a
burning building was to jump off the roof
 when forced to make a decision that goes against their beliefs, people will change their opinions
to match their actions; called cognitive dissonance
o for example, if subjects are paid to lie to other subjects about how fun the experiment
is, they will later self-report the experiment as actually being fun
o when confronted with decisions that lead to cognitive dissonance, people will do one of
three things:
 they will change their behavior to match their beliefs
 they will change their beliefs to match their behavior
 they will find justification for performing the action and maintaining their beliefs
o if you are an environmental activist, and you want to turn on AC even though it's bad for
the environment, you will…
 open a window instead (change behavior)
 decide that pollution isn't such a big deal (change beliefs)
 rationalize that one AC unit won't make a difference (justify both)
 risk-taking behaviors usually involve an approach-avoidance conflict
o if the benefit of risk-taking is greater than its potential cost, people will be more likely to
take the risk (represented as p>p)
o the greater the benefit relative to cost, the more likely they are to take the risk
o some people are more willing to take risks than others
 risk-sensitivity theory: people are more likely to take risks when they are at a severe
disadvantage
o birds are more willing to forage in open fields when they are starving
o mice enter novel homes when they absolutely have to hide
o male bats only mate before hibernation if they can't mate at any other time

79. o disadvantaged males take the biggest risks, especially when they have no mate or
offspring
 this is a by-product of polygyny, where only dominant males have their
reproductive fates assured
o still, females are forced to take specific risks (mating & STD's, pregnancy, birth, and
nurturance)
 Mishra et al performed this study in 2014:
o they wanted to evaluate risk-sensitivity theory using intelligence as a cue of competitive
advantage or disadvantage
o experimenters ran a fake intelligence test on several subjects, then gave them feedback
 participants were students, so intelligence was important to them
 students were told they were either…
 average
 above average
 or below average, regardless of their actual score
o students were then given a choice task: would you rather take $3 right now or have a
10% chance of getting $30?
 people who were marked above the class average took fewer risks
 people who were below average took more risks
o they did the same thing with a new set of participants
o for the most part this second trial was identical, but after the first task, students took
another intelligence test, received a different mark, and performed another choice task
 people who were first told they were above average and then told they were
below average (advantage-disadvantage) took the same number of risks
 disadvantage-advantage students took much fewer risks the second time
 disadvantage-disadvantage students took even more risks the second time
 disadvantage-control students, who did not take a second test but were given a
second risk task, were about as risky the second time
o authors did not find a sex difference, which could indicate that intelligence is as
important to males as it is to females
 delay of gratification
o sometimes you have to sacrifice short-term gains for long-term benefits
o in the Stanford marshmallow experiment…
 experimenters placed a marshmallow in front of a child and told them that if
they went 15 minutes without eating the marshmallow, they would get another
 children who were able to avoid eating the marshmallow went on to be more
academically and socially successful later in life
 children below the age of four have little impulse control; they always ate the
marshmallow
 after the age of four, individual differences in impulse control start to show;
these differences persist throughout their lives
o there are two types of self-regulation in the delay of gratification:
 "hot" strategies: emotional, impulsive, out of control
 hot strategies usually result in intense focus on the object, increasing
temptation, thinking about its appeal, and taking the immediate reward
 "cool" strategies: calm, controlled, cognitive
 cool strategies result in greater control over behavior throughout one's
life

80.  look at Maslow's hierarchy of needs
o the more basic a desire is, the harder it is to delay
o physiological needs are very hard to delay, followed by safety needs, love-related needs,
etc.
Part 14: Self, Family, and Community
 in the past, we've talked about primary emotions, like happiness, sadness, etc.
o these emotions can be observed in "simpler" mammals
 today, we will be discussing higher-order emotions, like embarrassment, shame, guilt, and pride
o these emotions are experienced solely by humans and some high-intelligence primates
o these emotions are not as direct, immediate, or observable as the primary emotions
o for an organism to experience these emotions, they must be able to interact socially,
interpret complex situations, and evaluate their own behavior
 why do we experience these emotions?
o we are a social species
o pride, embarrassment, guilt, etc. all affect the way we interact with others
o these emotions are elicited as a result of social interactions:
 praise is any social action that reinforces behavior in others
 clapping, cheering, smiling, raising pitch, saying "good job," etc.
 there are also tangible social rewards/praise, like promotions
 praise reinforces behavior by promoting pride, a positive emotion
distinct from happiness
 disapproval is social action that punishes others for their behavior
 frowning, upturned nose, shunning, lowering pitch, saying "you should
be ashamed," etc.
 again, there are tangible social punishments as well, like demotion
 disapproval punishes behavior by promoting shame, a negative emotion
distinct from sadness
 list of higher-order emotions:
o embarrassment occurs when something happens that threatens a person's reputation
 embarrassment can also be elicited when someone scrutinizes your behavior
 characterized by looking downward, smiling, and other self-
shrinking/appeasement behaviors
 blushing occurs
 heart rate may decrease
 blushing is caused by SNS activation, which usually also triggers an
increase in heart rate… what's happening?
 sequential PSNS activation occurs a few minutes after the embarrassing
moment, decreasing heart-rate before getting rid of the blush
 people gain the capacity for embarrassment around 2-3 years of age
 this is the age at which children usually start to recognize themselves
 after this age, every fully-developed toddler will show some form of
embarrassment
 embarrassment has adaptive value

81.  it acts as an apology for minor social transgressions by showing that you
are aware of your mistake
 people who show obvious signs of embarrassment are judged more
favorably than people who try to play it cool
o shame is similar to embarrassment, but more intense and less socially adaptive
 people generally don't mind feeling a little embarrassed, but they do not want
to feel shame
 embarrassment is a mix of foolishness, sadness, and surprise
 shame is a mix of fear, disgust, regret, and depressive affect
 embarrassment is attributed to simple mistakes and situational behavior; shame
is attributed to who you are as a person
 shame often comes from socially unacceptable beliefs/desires or a
failure to meet personal goals
 shame is associated with behavior that is seen to be stable, internal, and
beyond one's control; it's about who you are, and it can't be changed
 people only feel embarrassed for things they do in front of other people; shame
requires no audience
 because shame is not always a social phenomenon, it does not have as
much adaptive value
 shame often results in anger directed towards oneself and others
 people who are prone to experiencing shame often lack empathy for others
 susceptibility to shame is correlated with several disorders, including
psychopathy
 shame is a common antecedent of suicide
 people who repeatedly do things that lead to shame are more
susceptible to suicide
o pride occurs when something happens that improves a person's reputation
 pride is a unique emotional expression, distinct from happiness
 people can recognize pride in others without being prompted with the
word "pride" or even hearing the context of the situation
 characterized by head tilting back, visibly expanded posture, arms possibly
raised above the head, and a small smile
 pride usually comes from social interactions, but you don't need an audience to
feel proud
 people who frequently display pride tend to take on dominant roles in social
interactions and may also be perceived as more likeable
 Takahashi et al performed this experiment in 2008
 brought subjects into the lab, had them read certain phrases while lying
in an MRI machine
 phrases were either happy or prideful
 the "happy" phrases were certainly happy, but the happiness
had nothing to do with personal accomplishment, e.g. "I won
the lottery"
 the "prideful" phrases had everything to do with personal
accomplishment, e.g. "I was voted employee of the month"
 happy phrases activated the ventral striatum and insula, which are
associated with happiness and the reward mechanism

82.  this part of the brain also lights up when processing appetitive
stimuli, like food or sex
 prideful phrases activated the right posterior superior temporal sulcus
and left temporal pole, which are both associated with social cognition
and theory of mind
 social cognition: the encoding, storage, retrieval, and
processing of information related to emotions seen in other
people
 theory of mind: the ability to attribute mental states to oneself
and others; the ability to understand that other people's states
of mind may be different from your own
o empathy and sympathy are related but different
 sympathy: understanding another person's emotions; knowing what someone is
feeling
 empathy: experiencing another person's emotions; feeling what someone is
feeling
 you can't have empathy without sympathy
 you have to know what someone is feeling before you can feel it
yourself
 empathy is a pro-social behavior that helps people cope
 by experiencing someone else's sadness, we are motivated to help them
overcome
 empathy is present even in infancy
 parental guidance, specifically the mother's response in empathetic
situations, is vital to the development of empathy
 if the mother is empathetic, the child will be more likely to develop
empathy; if the mother is not empathetic, the child will become less
empathetic
 this is only true for children with strong attachments to their
mothers
 children with secure attachments to their mothers show more empathy
to distressed peers
 when children aged 1-2 observe a peer or adult in distress, their
reaction varies
 some ignore the distressed person ("it's not my problem")
 others become quiet and show facial expressions indicating
concern
 others become agitated, like they're overwhelmed by the
situation
 the response seen at this age is a good indicator of how
empathetic a child will be later in life
 empathy is also observed in primates
 primates have lots of muscles around their lips and eyes, so they can
make a variety of facial expressions that signal their emotions to others
 primates have good vision, so they can easily recognize facial cues
 other organisms use pheromones and chemical signals to elicit
emotion, but these do not produce what we would consider
"empathy"

83.  monkeys and apes interpret and respond to the emotions of others
 they are willing to follow social rules, though not as much as we
are
 if a monkey comes across another, sadder monkey, they won't
suddenly start smiling, because that would be inappropriate
 the physiology of empathy:
 people with lesions in the temporoparietal area, right hemisphere, and
amygdala all tend to show deficits in interpreting others' facial
expressions and emotions
 the primary visual cortex, fusiform gyrus, and right inferior frontal
gyrus are all involved in face perception
 damage to the inferior surface of the temporal lobe sometimes results
in a condition called prosopagnosia or "face blindness"
 when processing faces, the brain integrates all of the individual
features of a face into one recognizable whole
 people recognize things like : ) as a face, because our brain is
really good at integrating face-like patterns
 people with prosopagnosia can see individual parts of a face,
but they cannot integrate these parts
 psychopaths do not have empathy
 they may have sympathy, the ability to recognize others' emotions, but
they do not feel those emotions themselves
 psychopaths lack remorse, because they do not have an impression of
how their actions make others feel
 psychopaths see people as objects that can be used or manipulated
 they often have a pervasive pattern of disregard for or violation of other
people's rights
 psychopathy begins in childhood or early adolescence and continues
into adulthood
 basic psychopathic tendencies:
 irritability and aggression; psychopaths are angered easily and
are prone to frustrated outbursts
 reckless and impulsive behavior
 disregard for the truth
 possible causes of psychopathy:
 neurological malformation or damage
 a disturbed upbringing
 there is probably a genetic or inheritable component to
psychopathy
 psychopathy has some adaptive features
 when most people are trusting, a psychopath can take
advantage
 but if everyone was a psychopath, no one would work
together, and society would crumble
 thankfully, most people aren't psychopaths, so those
who are can take advantage of everyone else
 certain jobs tend to attract psychopaths
 lawyers, salespeople, CEO's, etc.

84.  these jobs all benefit from a lack of remorse