Pavlov's classic experiments on classical conditioning demonstrated that organisms can learn to associate neutral stimuli with biologically significant stimuli, as when his dogs learned to salivate to a tone that predicted food. Later research expanded on Pavlov's work to show the importance of cognitive processes and biological predispositions in conditioning, and that conditioning principles can help explain diverse phenomena like drug addiction, immune responses, phobias, and advertising effectiveness. Pavlov's work established classical conditioning as a fundamental form of learning and influenced the development of behaviorism.

1. Learning
How Do We
Learn?
http://www.youtube.com/watch?v=nKHxT7fDwN4

2. Definition
Learning is a relatively permanent change
in an organism’s behavior due to
experience.
Learning helps us adapt to our environment. Nature’s most important
gift to us may be our adaptability—our capacity to learn new
behaviors that enable us to cope with ever-changing experiences.
Learning also breeds hope. What we learn we can also teach to
others.

3. How Do We Learn?
The key to learning is experience. We learn by association. Our
minds naturally connect events that occur in sequence.
2000 years ago, Aristotle suggested this law of association. Then
200 years ago Locke and Hume reiterated this law.
The events linked in associative learning may be two stimuli (as
in classical conditioning) or a response and its consequences (as
in operant conditioning). In observational learning, we learn by
viewing others’ experiences and examples.

4. Associative Learning
Learning to associate one stimulus
with another. (classical conditioning)
This sea snail withdraws its gills when squirted with water. In its natural
habitat (i.e. choppy water) this response diminishes. However, if the squirt
is followed by an electric shock, the response becomes stronger. The snail
relates/associates the squirt of water to the impending shock.

5. Associative Learning
Learning to associate one stimulus
with another. (classical conditioning)

6. Associative Learning
Learning to associate a response
with a consequence. (operant conditioning)

7. Associative Learning
Learning to associate a response
with a consequence. (operant conditioning)

8. Associative Learning
• Ex: 11 Mexican Grey Wolves (which has been extinct in
the US since 1977) were bred and raised in captivity.
• They were released in the Arizona Apache National
Forest in 1988.
• After 8 months there was only one surviving wolf. They
had learned to hunt and move away from people but
they had not learned to be afraid of them and hence did
not run away from those with guns.
• This supports that successful adaptation requires both
nature (genetic predispositions) and nurture (history of
appropriate learning).

9. • Conditioning is the process of learning
associations. In this module (18/7ed or 17/8thed)
we will cover classical conditioning which is
when we learn to associate two stimuli and
anticipate the events.
• In the next module (19/7ed or 18/8ed), we look
at operant conditioning where we learn to
associate a response (our behavior) and its
consequences. We usually repeat those acts
that are followed by good rewards and avoid
those acts that are followed by bad results.

10. Classical Conditioning
Classical Conditioning: Module 17
 Pavlov’s Experiments
 Extending Pavlov’s Understanding
 Pavlov’s Legacy

11. Classical Conditioning
Ideas of classical conditioning originate from old philosophical
theories. However, it was the Russian physiologist Ivan Pavlov who
elucidated classical conditioning. His work provided a basis for later
behaviorists like John Watson. Watson and Pavlov shared: (1) a
disdain for mentalistic concepts such as consciousness and (2) a
belief that the basic laws of learning were the same for all animals –
whether dogs or humans.
Today classical conditioning is seen as a basic form of learning by
which all organisms adapt to their environment. However, it is
agreeable that the conscious and mental processes should not be
ignored either.
Sovfoto
Ivan Pavlov (1849-1936)

12. Pavlov’s Experiments
Before conditioning, food (Unconditioned
Stimulus, US) produces salivation
(Unconditioned Response, UR). However, the
tone (neutral stimulus) does not.

13. Pavlov’s Experiments
Pavlov would repeatedly present a neutral stimulus (such as a
tone) just before an unconditioned stimulus (US), such as
food, which triggered the unconditioned response (UR) of
salivation. After several repetitions, the tone alone (now the
conditioned stimulus [CS]) began triggering a conditioned
response (CR), salivation. Unconditioned means “unlearned”;
conditioned means “learned.” Thus, a UR is an event that
occurs naturally in response to some stimulus. A US is
something that naturally and automatically triggers the
unlearned response. A CS is an originally neutral stimulus
that, through learning, comes to be associated with some
unlearned response. A CR is the learned response to the
originally neutral but now conditioned stimulus.

14. Pavlov’s Experiments
During conditioning, the neutral stimulus (tone)
and the US (food) are paired, resulting in
salivation (UR). After conditioning, the neutral
stimulus (now Conditioned Stimulus, CS) elicits
salivation (now Conditioned Response, CR)

15. Conditioning
The bigger picture (in regards to
conditioning):
Conditioning helps an animal survive and
reproduce—by responding to cues that
help it gain food, avoid danger, locate
mates, and produce offspring.
http://www.youtube.com/watch?v=hhqumfpxuzI

16. Acquisition
Acquisition is the initial learning stage in classical
conditioning in which an association between a neutral
stimulus and an unconditioned stimulus takes place.
1. In most cases, for conditioning to occur, the neutral
stimulus needs to come before the unconditioned
stimulus.
2. The time in between the two stimuli should be about half
a second.
3. Responses acquired like this demonstrate how classical
conditioning is biologically adaptive because it helps
organisms prepare for good or bad events.

17. Acquisition
The CS needs to come half a second before the US
for acquisition to occur.

18. Extinction
Extinction refers to the diminishing of a conditioned response when
the conditioned stimulus occurs repeatedly without the
unconditioned stimulus.
When the US (food) does not follow the CS (tone), CR (salivation)
begins to decrease and eventually causes extinction.

19. Spontaneous Recovery
Spontaneous recovery is the reappearance, after a pause, of an
extinguished conditioned response.
After a rest period, an extinguished CR (salivation) spontaneously
recovers, but if the CS (tone) persists alone, the CR becomes
extinct again.

20. Stimulus Generalization
Tendency to respond to stimuli
similar to the CS is called
generalization. Pavlov conditioned
the dog’s salivation (CR) by using
miniature vibrators (CS) on the
thigh. When he subsequently
stimulated other parts of the dog’s
body, salivation dropped.
Generalization has survival value
because it extends a learned response to
other stimuli in a given category, for
example, fleeing from all dangerous
animals.

21. Stimulus Discrimination
Discrimination is the learned ability to distinguish between a
conditioned stimulus and other stimuli that do not signal an
unconditioned stimulus.
Discrimination has survival value because it limits our learned responses
to appropriate stimuli, for example, fleeing from a rampaging lion but
not from a playful kitten.

22. Taste Aversions
Taste aversions are particularly good for illustrating classical conditioning.
Perhaps you can share one of your own and explain it in terms of
conditioning principles. Example: Some years ago my instructor stored a
dinner in the freezer compartment of our department’s refrigerator. When
he went to retrieve it, he found it in the company of a frozen laboratory rat.
He learned that a student assistant, not knowing how to dispose of the
deceased animal, had carefully packaged it in plastic and temporarily
placed it in the freezer. Not only was he unable to eat the dinner in the
freezer, but now he finds all such dinners repulsive. Do you have any
experiences of your own?
Psychologist Paul Rozin states, “Many people find slimy foods upsetting or
anything with mucoid texture.” This is an example of what he calls
“secondary disgust,” disgust for something that looks or feels similar to
something disgusting in its own right. Rozin notes how subjects in one of
his experiments were presented with two pieces of chocolate fudge, one
shaped to look like a muffin, the other a replica of dog droppings. Guess
which one subjects avoided.

23. Taste Aversion
In the following exercise, react to the following tasteful situations described
by Rozin. Then, we will compare your responses to those of Rozin’s 143
subjects. You should respond on a 9-point scale from 1 = dislike extremely
through 5 = neutral to 9 = like extremely.
For the first four questions, dream up a bowl of your favorite soup, one that
would score an unqualified 9.
1. Now imagine that the soup was served to you in an ordinary bowl, but had
been stirred by a thoroughly washed, used flyswatter. How much would
you like to eat that soup?
2. If that flyswatter were brand new, how much would you like to eat the
soup?
3. If the soup was first stirred with a thoroughly washed but used comb, how
much would you like to eat it?
6. If the soup was served in a thoroughly washed, used dog bowl, how much
would you like to eat it?
Now fantasize about your favorite cookie, again one that would rate a 9.
5. How much would you like to eat this cookie if you’d dropped it on the
grass first?
6. How much would you like to eat it if a waiter had taken a bite first? an
acquaintance? a good friend?

24. Taste Aversion
Clearly, the association principle is everything when it comes to food. The
idea that something disgusting has been near a favorite dish puts most
people off, even when the food is germ-free. Here are Rozin’s results.
1. Eighty-two percent of Rozin’s subjects rated the “clean-flyswatter
soup” a 4 or less; they would dislike eating it.
2. Fifty-eight percent disliked this bowl of soup. Since the flyswatter is
brand new, it has less of an association with insects. However, the idea
that the soup had been stirred by an object that might meet a fly in the
future was enough to make some people pass it up.
3. Seventy-six percent disliked this soup. Presumably, the thought of
human hair is slightly less disgusting than insect contamination.
4. Seventy-one percent disliked soup served in a dog bowl.
5. Only 34 percent would want to pass up this cookie. There’s no
assurance of perfect cleanliness, but grass itself has few negative
associations for most of us.
6. Eighty-four percent would reject this cookie after a waiter had taken a
bite. Only 31 percent would refuse it after an acquaintance had taken a
bite, and just 16 percent, if a friend had taken a bite.

25. Extending Pavlov’s Understanding
Pavlov and Watson considered consciousness, or
mind, unfit for the scientific study of psychology.
However, they underestimated the importance of
cognitive processes and biological constraints.
Recap:
http://www.youtube.com/watch?v=DUa_F2OJT0k&feature=related

26. Cognitive Processes
Early behaviorists believed that learned
behaviors of various animals could be reduced
to mindless mechanisms.
However, later behaviorists suggested that
animals learn the predictability of a stimulus,
meaning they learn expectancy or awareness of a
stimulus (Rescorla & Wagner, 1972).

27. Biological Predispositions
Pavlov and Watson believed that laws of
learning were similar for all animals.
Therefore, a pigeon and a person do not differ
in their learning.
However, behaviorists later suggested that
learning is constrained by an animal’s biology.

28. The Importance of Cognitive Processes and Biological
Predispositions in Classical Conditioning
Research indicates that, for many animals, cognitive appraisals are important
for learning. That is, thoughts and perceptions are important to the
conditioning process. For example, animals appear capable of learning
when to expect an unconditioned stimulus. The more predictable the
association between the CS and the US, the stronger the CR.
The early behaviorists’ view that any natural response could be conditioned to
any neutral stimulus has given way to the understanding that each species
is biologically prepared to learn associations that enhance its survival.
Thus, humans are likely to develop an aversion to the taste of a
contaminated food but not to the sight of an associated restaurant, its
plates, or the music they heard there. Similarly, rats develop aversions to
tastes but not to sights or sounds. Conditioning occurs best when the CS
and the US have just the sort of relationship that would lead a scientist to
conclude that the CS causes the US.

29. Biological Predispositions
Courtesy of John Garcia
Garcia showed that the duration
between the CS and the US may be
long (hours), but yet result in
conditioning. A biologically adaptive John Garcia
CS (taste) led to conditioning but
other stimuli (sight or sound) did
not.

30. Biological Predispositions
Even humans can develop classically to
conditioned nausea.

31. Pavlov’s Legacy
Pavlov’s greatest contribution
to psychology is isolating
elementary behaviors from
more complex ones through
objective scientific
procedures.
Ivan Pavlov
(1849-1936)

32. Pavlov’s Legacy
Pavlov taught us that principles of learning apply across species and that
classical conditioning is one way that virtually all organisms learn to adapt
to their environment. Pavlov also demonstrated that significant
psychological phenomena can be studied objectively. Finally, Pavlov
taught us that conditioning principles have important applications such as
how to treat fear.
Classical conditioning principles provide important insights into drug abuse
and how it may be overcome. Classical conditioning works on the body’s
disease-fighting immune system. For example, when a particular taste
accompanies a drug that influences immune responses, the taste by itself
may come to produce those immune responses. Watson’s “Little Albert”
study demonstrated how classical conditioning may underlie specific fears.
Today, psychologists use extinction procedures to control our less adaptive
emotions and condition new responses to emotion-arousing
stimuli.

33. Applications of Classical
Conditioning
1. Former drug users often feel a craving when they
are again in the drug-using context—with people or
in places they associate with previous highs. This,
drug counselors advise addicts to steer clear of
people and settings that may trigger theses
cravings.
2. Classical conditioning even works on the body’s
disease-fighting immune system. When a particular
taste accompanies a drug that influences immune
responses, the taste by itself may come to produce
an immune response.

34. Applications of Classical
Conditioning
Watson used classical
conditioning procedures to
develop advertising
campaigns for a number of
organizations, including
Maxwell House, making the
“coffee break” an American
Brown Brothers
custom.
John B. Watson

35. Little Albert
Human behaviors and emotions are
biologically influenced, however they are
also greatly learned and are hence a
bundle of conditioned responses.
Case: Little Albert—he feared loud noises
like most infants, but he did not fear rats.
He was conditioned to fear rats and then
generalized that fear to other things as
well.
http://www.youtube.com/watch?v=Xt0ucxOrPQE&feature=related