3. “Learning is essential to human
behavior. From the classroom to
the trading floor to ordering at a
restaurant, our ability to make
good decisions is shaped by how
we learn from experience.”
-Daphna Shohamy
Biology of Learning and Memory
4. 13 Learning and Memory
What is the nature of learning?
Learning is the process by
which experiences change
our nervous system, and
hence our behavior.
We call those changes
memories.
5. 13 Overview
Four basic forms of learning:
• Perceptual learning
• S-R (associative) learning
• Motor learning
• Relational learning
7. • Neurobiologists
generally believed that
memories were
generally not the result
of new neuron
production
• 1894: Santiago Ramon
y Cajal thought
memories were formed
by strengthening
neuron connections
• 1949: Hebbian theory
13 Early Learning Theory
9. • Changes in the structure or biochemistry
of synapses that alter their effects on
postsynaptic neurons
• Long-term Potentiation: long term
increase in the excitability of a neuron to a
particular synaptic input caused by
repeated high-frequency activity of that
input.
• Long-term Depression: produces a long-
lasting decrease in synaptic strength.
13 Synaptic Plasticity
10. • Associative long-term potentiation:
weak synapses are strengthened by the
action of strong synapses
• NMDA receptor: A specialized ionotropic
glutamate receptor that controls a calcium
channel that is normally blocked by Mg2+
ions; involved in long-term potentiation.
• AMPA receptor: An ionotropic glutamate
receptor that controls a sodium channel;
when open, it produces EPSPs.
13 Synaptic Plasticity
11. 13 Perceptual Learning
• Involves learning to recognize things, not what
to do when they are present
• Can involve learning to recognize entirely new
stimuli, or it can involve learning to recognize
changes or variations in familiar stimuli
• We learn that particular stimuli are found in
particular locations or contexts or in the
presence of other stimuli. We can even learn
and remember particular episodes: sequences
of events taking place at a particular time and
place.
12. • Thalamus LGN -> primary visual cortex ->
extrastriate cortex
• Objects are recognized visually by circuits
of neurons in the visual association cortex.
• Damage to the inferior temporal cortex
leaves vision unaffected but causes
inability to discriminate visual stimuli
• Ventral = what, Dorsal = where
13 Perceptual Learning
13. • Involves changes in synaptic connections
in the visual association cortex , creating
new neural circuits
• When exposed to the same stimulus, the
same circuits become active
13 Perceptual Learning
16. • MT/MST: region of the visual association
cortex that perceives movement
• Memory contains information about
previously seen movements
• Brain saves sensory information for future
reference
13 Perceptual Learning
17. • The memory for a stimulus or an event
that lasts for a short while
• Involves activating established neural
circuits even after stimulus is gone
• Delayed matching-to-sample task: A
task that requires the subject to indicate
which of several stimuli has just been
perceived.
13 Short-term Memory
19. • Involves several brain regions
• Prefrontal cortex manipulates and
organizes information to be remembered
• PFC devises strategies for retrieval and
monitors the outcome of those processes
• Successful remembering requires: filtering
out irrelevant info and maintaining relevant
info
13 Short-term Memory
21. 13 S-R Learning
Hebb’s rule: Neurons that fire together, wire together.
S-R Learning is to learn to perform a particular
behavior when a particular stimulus is present
22. Ivan Pavlov
While studying salivation in
dogs, Pavlov “stumbled”
upon the principles of
classical conditioning.
13 S-R Learning
23. In classical (Pavlovian) conditioning, a neutral
stimulus is paired with another stimulus that elicits a
response.
Eventually, the neutral stimulus by itself will elicit the
response.
13 S-R Learning
27. B.F. Skinner
13 S-R Learning
He was a firm believer
that any human action
was the result of the
consequences of that
same action.
28. In instrumental
(operant) conditioning,
an association is made
between:
• Behavior (the
instrumental response)
• The consequences of
the behavior (the
reward).
13 S-R Learning
30. The Reinforcement System
13 S-R Learning
Detect the presence of
a reinforcement
stimulus.
Strengthen the neural
connections between
the discriminative
stimulus and the
instrumental response.
34. • Iconic memories are the briefest
memories and store sensory impressions
that only last a few seconds.
• Short-term memories (STMs) usually last
only for up to 30 seconds or throughout
rehearsal.
Short-term memory is also known as
working memory.
13 Memory
I work out!
35. • An intermediate-term memory (ITM)
outlasts a STM, but is not permanent.
• Long-term memories (LTMs) last for
days to years.
13 Memory
36. 13 Relational Learning
Henry Molaison suffered
from severe epilepsy.
Because of seizures, a
decision was made to
remove the amygdala, the
hippocampus, and some
cortex.
Patient H.M.
37. • Retrograde amnesia
is the loss of memories
formed before onset of
amnesia and is not
uncommon after brain
trauma.
• Anterograde amnesia
is the inability to form
memories after onset
of amnesia.
13 Relational Learning
H.M. had normal short-term
memory but had severe
anterograde amnesia.
38.
39. Dissociation of explicit (declarative) memory, which
was impaired vs.
Implicit (nondeclarative) memory, which was fine
13 Relational Learning
40. • Declarative memory
deals with what—facts
and information acquired
through learning that can
be stated or described.
(Things we are aware that
are learned.)
• Nondeclarative
(procedural) memory
deals with how—shown by
performance rather than
conscious recollection.
13 Memory
Two kinds of long-term memory:
