physiologi learn

1. Physiology of Learning dr. Legiran, M.Kes
• WHAT DO YOU THINK?
– Can your brain grow new cells?
– Does what you eat and drink affect your
brain?
– Do colors influence emotion?
– Can knowledge of “brain- based” learning
positively influence learning?
– How are you already using brain based
approaches to learning in your lessons?

2. How is your brain like(?)
• A cabbage
• A raisin
• A pillowcase
• A grapefruit
• String cheese
• A walnut

3. Our Brains
• Are like a “jungle”- nothing “runs”
the jungle
• All parts of the brain participate
with each other, while each has
its own function
• There is natural pruning or neural
pruning that occurs when parts are not used (this
may be why sounds not heard or used atrophy
over time)
• “LEARNING IS A DELICATE, BUT IS A
POWERFUL DIALOGUE BETWEEN GENETICS
AND THE ENVIRONMENT…” Robert Sylwester, A
Celebration of Neurons

4. Brain’s Complexity
• Cellular level - three pints of liquid, three
pounds of mass, tens of billions of nerve
cells (or neurons), ten times more
numerous glial cells that support, insulate
and nourish the neurons
• Brain cells - 30 thousand neurons (300,000
glial cells) fit into the space of a pinhead.

5. Parts of the Brain
• Brainstem (survival )
• Cerebellum ( autonomic nervous system)
• Limbic system (emotion)
• Cortex ( reason/logic)
Brainstem
Cerebellum
Cortex

6. • Frontal lobe - Cortex
– Creativity- Judgment - Optimism - Context
– Planning - Problem solving - Pattern making
• Upper temporal lobe - Wernicke’s Area
– Comprehension - Relevancy - Link to past (experience) - Hearing
- Memory - Meaning
• Lower frontal lobe - Cortex
– Speaking/language - Broca’s area
• Occipital lobe - Spatial order
– Visual processing - Patterns - Discovery
• Parietal lobe
– Motor - Primary Sensory Area - Insights - Language functions
• Cerebellum
– Motor/motion - Novelty learning - cognition - balance - posture

7. Broca’s
area
Pars
opercularis
Motor cortex Somatosensory cortex
Sensory associative
cortex
Primary
Auditory cortex
Wernicke’s
area
Visual associative
cortex
Visual
cortex
Language and Thought
Grammar
and word
production
Movement and joint positions
Cerebellum

8. Neurons
• Connect to other neurons,
to muscles, or glands
• Send and receive chemical information
(messages) for behaviors
• Can be a millimeter in length or as long as
a meter
• Cells nucleus contains DNA (As long a
meter)

10. • Neurons contain tubular extensions that are
designed to communicate quickly with
specific cells in the body network - this is a
transportation system, much like a phone
system.
• The brain has both nerve cells and glial
cells. The neurons are cellular agents of
cognition; the glial cells act as a scaffolding
or insulation for impulses. (The insulation
increases the speed of the neural (electrical)
messages.)

11. Memory
• Place to store information, as in: “How
much memory does your hard drive
have?”
• Information that gets stored, as in: “I have
fond memories of my summer vacation.”
• retention of learned information
• Learning: acquisition of
knowledge/information

12. Memory
– Thompson
• many structures involved in memory
formation;
• memory depends on many mechanisms;
• classical conditioning of eyelid responses in
rabbit – response occurs in cerebellum -
lateral interpositus nucleus (LIP)

13. The Modal Model of Human
Memory

14. Memory stores
Sensory Memory
Short-Term
Memory
Long-Term
Memory
Capacity Very large 7±2 items Infinite
Duration
Very short (Fraction
of second)
Short (Fraction of
minute)
Indefinite
Format
(Coding)
Direct representation
of sensual
experience as action
potentials
Spoken language
format
Semantic
(meaningful)
format

15. Processes
Attention
Selects portion of Sensory Memory for further processing by
STM
Ex: Attend to lecture, not sound of ventilation system.
Chunking
Group items into meaningful units
Strategy to increase capacity of STM
Ex: 270-348-8-0-8-0
Rehearsal
Repeat information until no longer needed.
Strategy to increase duration of STM
Ex: 8080… 8080… 8080…Oops, what was that number?
Encoding
Information moved from STM to LTM.
Ex: Studying to learn the answers to the test questions.
Retrieval
Information moved from LTM to STM
Ex: Remembering the answer to the question so that you can
write it down.

16. Four Theories of Forgetting from Long-Term
Memory
Explanation Description Example
Encoding
Failure
•Information never encoded
from
STM to LTM.
•Student “studies” for exam
while
watching TV, can’t “remember”
answers to test questions.
Decay
•Information encoded in
LTM, but decays over time
with lack of use.
•However, some memories
never decay, even though
they are not frequently
used.
•Decay can be explained by
interference.
•Ebbinghaus memorized
nonsense
words, tested his memory of
these days later, found
“forgetting curve.”

17. Four Theories of Forgetting … (cont’d)
Explanation Description Example
Interference
•Information encoded in LTM,
but cannot be retrieved
because newer
information interferes.
•Can be thought of as
“retrieval error.”
•Accounts for Ebbinghaus’s
findings, without memories
decaying.
•Can’t remember old phone
number; recall new number
instead.
Repression
•According to Freud, painful
memories can be pushed
below level of consciousness.
•Very controversial topic;
many psychologists now
argue that repression does
not occur.
•Memories of child abuse suddenly
recalled during psychotherapy (But
are they accurate?)
•“Recovered Memory Syndrome” –
false memories planted during
hypnosis or drug therapy.
•Loftus’s “Lost in the Mall”
experiment.

18. Types of LTM

19. Memory and learning
• Types of memory:
– declarative
• facts and events
• conscious recollection
• easy come easy go
– procedural
• learning to play an instrument, to ride a bike;
• no conscious recollection (usually);
• need repetition or training;
• longer retention

20. Memory and learning
• Subtypes of declarative memory:
– short-term memory
• temporary,
• limited capacity,
• needs rehearsal (e.g. telephone number)
– long-term memory
• 'permanent'
• greater capacity
• no continual rehearsal needed

22. Theories of memory storage
• Engram
– Engram was a hypothetical structure or
feature inside of the neuron that stored
information
– “Grandmother” cell – the neuron that fired
when you see your grandmother
– In computers, information (memories) stored
in “cells” or “slots” of hard drive
– But this is not how the nervous system
stores information!

23. Theories of memory storage …
• Long-Term Potentiation (LTP)
– Recent research indicates that memories are stored
in the synapses between neurons
– Learning involves formation and modification of
synapses
– “Neurons that fire together wire together”
– LTP takes days to complete – learning spaced over
several days more effective at inducing LTP than
learning crammed into short period of time
– Most research on LTP done on sea slug Aplysia

24. Memory and learning
• Plasticity paradigms:
– Associative mechanisms:
• classical conditioning
pairing of 2 stimuli changes the response to one of them
(Pavlov)
– conditioned stimulus (CS) - originally neutral (no
response)
– unconditioned stimulus (UCS) - automatically evokes
response – unconditioned response (UCR)
– after repetitive pairing of CS and UCS presentation of CS
evokes learned response - conditioned response (CR)
• operant conditioning - reinforcement and punishment

25. Memory and learning
– Nonassociative mechanisms:
• habituation
decrease in response to a repeated stimulus not
accompanied by changes in other stimuli
• sensitisation
an increase in response to a moderate stimuli as a
result of a previous exposure to a strong stimulus

26. Memory and learning
– memory consolidation - storing knowledge
in the long-term memory
• Hebb - reverberating circuit - prolonged
excitation leads to chemical or structural changes
• Memory of meaningful or emotional facts
enhanced
• involvement of amygdala (stimulation of
hippocampus and cortex)
• damage to amygdala impairs emotional
enhancement of memories

27. Memory and learning
– working memory - modification of the concept
of short term memory
• memory consolidation may take place with or without use of
the short-term memory
• a phonological loop
• a visuo-spatial sketchpad
• the central executive - directs attention towards stimuli;
determines what will be stored in the working memory
• working memory test - delayed response task - higher activity in
the prefrontal cortex during the delay

28. Physiology of Memory
Types of amnesia
1. Retrograde amnesia
– Loss of memories already formed due to
brain damage
– But can still form new LTMs
– Example: Patient has stroke and no longer
recognizes family members.
– Common symptom of Alzheimer’s disease

29. Physiology of Memory …
Types of amnesia …
2. Anterograde amnesia
– Loss of ability to form new long-term
memories
– Previously stored memories may still be
intact
– Korsakoff’s syndrome – You meet patient,
tell him your name, he can repeat it – You
leave room, come back 2 minutes later, he
doesn’t know who you are.

30. Hippocampus
• Thought to play a role in encoding
information from STM to LTM
• Case of H.M.
– Both hippocampi removed to control severe epilepsy
– No problems with short-term memory
– Lost ability to form new long-term memories
(anterograde amnesia)
– LTM intact for events until shortly before surgery
– Symptoms similar to Korsakoff’s syndrome, but
different area of brain affected

31. Memory and learning
• Hippocampus
– H. M. - removal of hippocampus:
• Retrograde amnesia (loss of memory for events
occurring shortly before brain damage)
• intact short-term/working memory
• acute anterograde amnesia (declarative memory)
(loss of memory for events happening after the
brain damage)
• intact procedural memory
• better implicit than explicit memory

32. Memory and learning
• Theories of the hippocampal function:
– declarative, explicit memory
• supported by the H.M. case
• hippocampal damage may impair implicit memory
• it does not damage all the memory in nonhumans
in tasks similar those requiring declarative memory
from humans
– dependence on the experimental protocol in
delayed matching-to-sample and delayed
nonmatching-to-sample task experiments

33. Memory and learning
– spatial memory
• rat maze experiments
• hippocampus is involved also in nonspatial aspects of the
tasks
– configural learning
• the meaning of the stimulus depends on what other stimuli
are paired with it, e.g. A + food; B + food; AB + no food
• hippocampus is involved in nonconfigural learning if its
sufficiently difficult
– binding memories
• input from many parts of cortex (‘secondary’ and ‘tertiary’
areas)

34. Memory and learning
• Brain damage and memory
– Korsakoff's syndrome – brain damage due to
prolonged deficiency in thiamine (B1).
• Thiamine deficiency
• loss of neurons in dorsomedial thalamus
• damage to prefrontal cortex
• apathy, confusion, retrograde and anterograde amnesia;
• better implicit memory (good at priming tasks);
• impaired reasoning about own memories;
• confabulation;

35. Memory and learning
– Alzheimer's disease
• forgetfulness, proceeding into serious memory loss
• confusion, depression, restlessness
• hallucinations
• sleeplessness, loss of appetite
• impaired procedural memory, explicit memory, attention.
• Genetic involvement;
• excessive accumulation of beta-amyloid plaques
• atrophy of cerebral cortex (esp. entorhinal), hippocampus
• formation of neurofibrillary tangles

36. Memory and learning
• Physiology of learning and memory
– Hebbian learning
• a cell A that successfully stimulated cell B in the
past becomes more successful in the stimulation of
B in the future
– Hebbian learning and classical conditioning
– Single cell mechanisms of invertebrate
plasticity
• Aplysia

37. Memory and learning
– habituation – depends on a change in
synapse between the sensory and motor
neuron

38. Memory and learning
– Sensitisation
• strong skin stimulation
• excitation of facilitating interneuron
• serotonine release on presynaptic terminals of
sensory neurons
• metabotropic effects
• prolonged action potential
• longer opening of voltage-gated calcium channels
• greater transmitter release per action potential

39. Memory and learning
– associative learning
• similar to the sensitisation
• pairing the CS (conditioned stimulus) and UCS
(unconditioned stimulus) increases presence of
calcium in the presynaptic terminal (due to CS)
• Intensified metabotropic effects
• More transmitter released than in sensitisation

40. Memory and learning
• Physiology of vertebrate plasticity
– long term potentiation (LTP)
a response enhancement at certain synapses due to rapid
intensive stimulus delivered simultaneously to a neuron by
several axons
• underlying mechanisms vary between the brain areas
• prominent in hippocampus
• attractive as a cellular basis of learning and memory:
• Specificity –only the active synapses become strengthened
• Cooperativity – simultaneous (almost) stimulation
produces LTP
• Associativity – LTP is hebbian (no need for action potential
– depolarisation sufficient)

41. Memory and learning
– Biochemistry of LTP – main actors:
• Glutamate receptors
• AMPA – opens sodium channels
• NMDA – allows sodium and calcium ions to enter
the neuron
– responds to glutamate ONLY when the membrane is
partly depolarised
» removal of magnesium ions blocking NMDA
receptors
• glutamate excitation of NMDA receptors opens
NMDA-dependent calcium channels

42. Memory and learning
• large influx of calcium activates protein kinases:
» protein kinase C (PKC)
» CaMKII (calcium calmodulin-dependent protein
kinase)
• alteration the structure (phosphorylation) of AMPA
receptors
• conversion of some NMDA receptors into AMPA
receptors
• creation of more AMPA receptors
• increased dendritic branch growth
• increased dendritic responsiveness to subsequent
incoming of glutamate

43. Memory and learning
– Long term depression (LTD)
a prolonged decrease in response to synaptic
input repeatedly paired to another input at a
low frequency
– LTP (LTD) may be involved in memory
formation - recently questioned

44. Memory and learning
– Potential problems with LTP/LTD as correlates
of memory formation:
• Importance of protein phosphorylation
• Protein phosphorylation is not permanent
• protein molecules are not permanent (app. 2
weeks lifetime)

45. Memory and learning
– Alternative mechanisms:
• continual phosphorylation of proteins
– main suspect: persistently active protein kinases (PKC)
– large elevation of calcium activates calpain (enzyme)
– breaking the peptide bond between regulatory and
catalytic parts of PKC
– freeing the catalytic region (remains active) leading to
continual proteins phosphorylation
– problem with PKC solution – limited time (minutes to
hours – but Bruce’s work)

46. Memory and learning
• protein synthesis
– evidence from experiments with protein synthesis
inhibitors
» animals injected with these inhibitors learn normally
but fail to recall during later testing
• structural changes
– change in the number of synapses
– morphological reorganisation

47. Techniques to Help Memory
• Define the “gist” - OVERVIEW
• Sequence events
• Plot out pictorially the information
• Tell the information to others in own
words - TALK
– Peer teaching/tutoring
• Amplify by giving examples
• Use multiple parts of the brain
(emotional, factual, physical)
– Auditory, Visual, Kinesthetic, Talk
– Combine
• Use color effectively
– Yellow and orange as attention-getters

48. The Brain is a Social Brain
12
• The brain develops better in concert with others
 When students have to talk to others about
information, they retain the information longer and
more efficiently!
 Make use of small groups,
discussions, teams, pairings,
and question and answer
situations.