Memory - Form and function

Chairperson
Dr. T. Kumanan MD., DPM, Professor
Dr. S. J. X. Sugadev MD., Assistant Professor
Slide 1
Presented by
Dr. A. M. Anusa
First Year PG
Prepared by
Prof. Rooban T,
Oral & Maxillofacial Pathologist

 Origin of word from
 Greek God - Mnemosyne
Slide 2

 Neurobiology of memory
 Identifying where and how different types of
information are stored
 Hypothesis by Hebb
 Memory results from synaptic alterations
 Study of simple invertebrates
 Synaptic alterations underlie memories
(procedural)
 Electrical stimulation of brain
 Experimentally produce measurable synaptic
alterations - dissect mechanisms
Slide 3

 Declarative and procedural
memories
 Nonassociative Learning
 Habituation
▪ Learning to ignore
stimulus that lacks
meaning
 Sensitization
▪ Learning to intensify
response to stimuli
Slide 4

 Associative Learning
 Classical Conditioning
Slide 5

 Associative Learning (Cont’d)
 Classical Conditioning
▪ Associates a stimulus that evokes response-
unconditional stimulus with second stimulus that
does not evoke response- conditional stimulus
 Instrumental Conditioning
▪ Experiment by Edward Thorndike
▪ Complex neural circuits due to motivation
Slide 6

 Experimental advantages in using
invertebrate nervous systems
 Small nervous systems
 Large neurons
 Identifiable neurons
 Identifiable circuits
 Simple genetics
Slide 7

 Nonassociative Learning in Aplysia
Slide 8

(Cont’d)
 Habituation of the Gill-Withdrawal Reflex
Slide 9

(Cont’d)
 Sensitization of the Gill-Withdrawal Reflex
Slide 10

 Associative
Learning in
Aplysia
 Classical
conditioning
 CS-US pairing
▪ Cellular level
▪ Molecular level
Slide 11

 The molecular basis for classical
conditioning in Aplysia
Slide 12

 Neural basis of memory learned from
invertebrate studies
 Learning and memory can result from
modifications of synaptic transmission
 Synaptic modifications can be triggered by
conversion of neural activity into intracellular
second messengers
 Memories can result from alterations in
existing synaptic proteins
Slide 13

 Synaptic Plasticity in the Cerebellar Cortex
 Cerebellum: Important site for motor learning
 Anatomy of the Cerebellar Cortex
▪ Features of Purkinje cells
▪ Dendrites extend only into molecular layer
▪ Cell axons synapse on deep cerebellar nuclei neurons
▪ GABA as a neurotransmitter
Slide 14

 The structure of the cerebellar cortex
Slide 15

 Long-Term Depression in the Cerebellar Cortex
Slide 16

(Cont’d)
(Cont’d)
▪ Cerebellar LTD and Classical Conditioning in Aplysia
▪ Similarity: Input-specific synaptic modification
▪ Dissimilarity: Site of convergence and nature of synaptic
changes
Slide 17

(Cont’d)
 Mechanisms of cerebellar LTD
▪ Learning
▪ Rise in [Ca2+]i and [Na+]i and the activation of protein
kinase C
▪ Memory
▪ Internalized AMPA channels and depressed excitatory
postsynaptic currents
Slide 18

 Synaptic Plasticity in the Hippocampus
 LTP and LTD
▪ Key to forming declarative memories in the brain
 Bliss and Lomo
▪ High frequency electrical stimulation of excitatory
pathway
 Anatomy of Hippocampus
▪ Brain slice preparation: Study of LTD and LTP
Slide 19

(Cont’d)
 Anatomy of the Hippocampus
Slide 20

(Cont’d)
 Properties of LTP in CA1
Slide 21

 Synaptic Plasticity in
the Hippocampus
(Cont’d)
 Mechanisms of LTP in
CA1
▪ Glutamate receptors
mediate excitatory
synaptic transmission
▪ NMDARs and AMPARs
Slide 22

(Cont’d)
 Long-Term Depression in CA1
Slide 23

 Synaptic Plasticity in the
Hippocampus (Cont’d)
 BCM theory
▪ When the postsynaptic cell
is weakly depolarized by
other inputs: Active
synapses undergo LTD
instead of LTP
▪ Accounts for bidirectional
synaptic changes (up or
down)
Slide 24

(Cont’d)
 LTP, LTD, and Glutamate Receptor Trafficking
▪ Stable synaptic transmission: AMPA receptors are
replaced maintaining the same number
▪ LTD and LTP disrupt equilibrium
▪ Bidirectional regulation of phosphorylation
Slide 25

 LTP, LTD, and Glutamate Receptor
Trafficking (Cont’d)
Slide 26

Slide 27

 Synaptic Plasticity in the Hippocampus (Cont’d)
 LTP, LTD, and Memory
▪ Tonegawa, Silva, and colleagues
▪ Genetic “knockout” mice
▪ Consequences of genetic deletions (e.g., CaMK11
subunit)
▪ Advances (temporal and spatial control)
▪ Limitations of using genetic mutants to study
LTP/learning: secondary consequences
Slide 28

 Phosphorylation as a long term
mechanism: Problematic
(transient and turnover rates)
 Persistently Active Protein Kinases
 Phosphorylation maintained:
Kinases stay “on”
▪ CaMKII and LTP
▪ Molecular switch hypothesis
Slide 29

 Protein Synthesis
 Requirement of long-term memory
▪ Synthesis of new protein
 Protein Synthesis and Memory Consolidation
▪ Protein synthesis inhibitors
▪ Deficits in learning and memory
 CREB and Memory
▪ CREB: Cyclic AMP response element binding protein
Slide 30

 Protein Synthesis (Cont’d)
 Structural Plasticity and Memory
▪ Long-term memory associated with formation of
new synapses
▪ Rat in complex environment: Shows increase in
number of neuron synapses by about 25%
Slide 31

 Learning and memory
 Occur at synapses
 Unique features of Ca2+
 Critical for neurotransmitter secretion and
muscle contraction, every form of synaptic
plasticity
 Charge-carrying ion plus a potent second
messenger
▪ Can couple electrical activity with long-term changes
in brain
Slide 32

Chapter 6 – Human Memory:
Encoding and Storage

 First rigorous investigation of human
memory – 1885.
 Taught himself nonsense syllables
 DAX, BUP, LOC
 Savings – the amount of time needed to
relearn a list after it has already been
learned and forgotten.
 Forgetting function – most forgetting
takes place right away.

 Atkinson & Shiffrin – proposed a three-
stage model including:
 Sensory store – if attended goes to STM
 Short-term memory (STM) – if rehearsed goes
to LTM
 Long-term memory (LTM)
 No longer the current view of memory.
 Still presented in some books.

Environment Sensory store
Short-term
(working) memory Long-term memory
Responses
Executive control processes
Sensation/perception Attention
encoding
retrieval

Environment Sensory store
Short-term
(working) memory Long-term memory
encoding
retrieval
1-3 seconds 15-25 seconds 1 sec to a lifetime

 Holds info when it first comes in.
 Allows a person to extract meaning from
an image or series of sounds.
 Sperling’s partial report procedure:
 A display of three rows of letters is presented.
 After it is taken away, a tone signals which
row to report.
 Subjects were able to report most letters.

A medium tone
signals the subject
to report the letters
in this row

 Iconic memory – visual
 Bright postexposure field wipes out memory
after 1 sec, dark after 5 sec.
 Echoic memory – auditory
 Lasts up to 10 sec (measured by ERP)
 Located in the sensory cortexes.

 The original idea is that when info in
sensory memory is paid attention to,
it moves into short term memory.
 With rehearsal, it then moves into
long term memory.
 STM has limited capacity, called
memory span.
 Miller’s magic number (7 ± 2)
 New info pushes out older info (Shepard)

Number of
intervening items
Probability of recalling
the target item

 Rate of forgetting seemed to be quicker
than Ebbinghaus’s data, but is not really.
 Amount of rehearsal appeared to be
related to transfer to long-term memory.
 Later it was found that the kind of rehearsal
matters, not the amount.
 Passive rehearsal does little to achieve long-
term memory.
 Information may go directly to LTM.

 Craik & Lockhart – proposed that it is not
how long material is rehearsed but the
depth of processing that matters.
 Levels of processing demo.

 Baddeley – in working memory speed of
rehearsal determines memory span.
Articulatory loop – stores whatever can be
processed in a given amount of time.
 Word length effect: 4.5 one-syllable words
remembered compared to 2.6 long ones.
 1.5 to 2 seconds material can be kept.
 Visuopatial sketchpad – rehearses images.
 Central executive – controls other systems.

 Delayed Matching to Sample – monkey
must recall where food was placed.
 Monkeys with lesion to frontal cortex cannot
remember food location.
 Human infants can’t do it until 1 year old.
 Regions of frontal cortex fire only during
the delay – keeping location in mind.
 Different prefrontal regions are used to
remember different kinds of information.

 In primates, working memory is localized
to the frontal cortex.
 Delayed matching to sample task:
 Monkeys are shown food that is then hidden.
 Later they are given a chance to locate it.
 Monkeys with frontal lobe lesions cannot
do this task.

 Activation – how available information is
to memory:
 Probability of access – how likely you are to
remember something.
 Rate of access – how fast something can be
remembered.
 From moment to moment, items differ in
their degree of activation in memory.

 ACT – Adaptive Control of Thought
 Moses Effect -- subjects shown the
words Bible, animal and flood should
recall Noah but recall Moses instead.
 When given the word flood they think of
Mississippi or Johnstown but not Noah.
 Why? Recall is based on both baseline
and activation from associated
concepts.
 Moses and Jesus have higher baselines.

 How recently we have used the memory:
 Loftus – manipulated amount of delay
 1.53 sec first time, then 1.21, 1.28, and 1.33
with 3 items intervening.
 How much we have practiced the memory
– how frequently it is used.
 Anderson’s study (sailor is in the park)

 Activation spreads along the paths of a
propositional network.
 Related items are faster to recall.
 Associative priming – involuntary spread
of activation to associated items in
memory.
 Kaplan’s dissertation – cues to solving riddles
hidden in the environment led to faster
solutions.

 Meyer & Schvaneveldt – spreading
activation affects how quickly words are
read.
 Subjects judged whether pairs of related &
unrelated items were words.
 Judgments about related words were faster.

 The amount of spreading activation
depends on the strength of a memory.
 Memory strength increases with practice.
 Greater memory strength increases the
likelihood of recall.

 Each time we use a memory trace, it
gradually becomes a little stronger.
 Power law of learning:
 T = 1.40 P-0.24
 T is recognition time, P is days of practice.
 Linear when plotted on log-log scale.

 Neural changes may occur with practice:
 Long-term potentiation (LTP) in
hippocampus.
 Repeated electrical stimulation of neurons
leads to increased sensitivity.
 LTP changes are a power function.

 Better memory occurs for items with
stronger brain processing at the time of
study:
 Words evoking higher ERP signals are better
remembered later.
 Greater frontal activation with deeper
processing of verbal information.
 Greater activation of hippocampus with better
long-term memory.

Words activate left
prefrontal cortex
Pictures activate right
prefrontal cortex
Hemodynamic =
blow flow during
brain activity

 Study alone does not improve memory –
what matters is how studying is done.
 Shallow study results in little improvement.
 Semantic associates (tulip-flower) better
remembered than rhymes (tower-flower),
81% vs 70%.
 Better retention occurs for more
meaningful elaboration.

 Elaboration – embellishing an item with
additional information.
 Anderson & Bower – subjects added
details to simple sentences:
 57% recall without elaboration
 72% recall with made-up details added
 Self-generated elaborations are better
than experimenter-generated ones.

 Stein & Bransford – subjects were given
10 sentences. Four conditions:
 Just the sentences alone – 4.2 adjectives
 Subject generates an elaboration – 5.8
 Experimenter-generated imprecise elaboration
– 2.2
 Experimenter-generated precise elaboration –
7.8
 Precision of detail (constraint) matters,
not who generates the elaboration.

 PQ4R method – use questions to guide
reading.
 64% correct, compared to 57% (controls)
 76% of relevant questions correct, 52% of
non-relevant.
 These study techniques work because
they encourage elaboration.
 Question making and question answering both
improve memory for text (reviewing is better
than seeing the questions first).

 Elaboration need not be meaningful –
other sorts of elaboration also work.
 Kolers compared memory for right-side-up
sentences with upside-down.
 Extra processing needed to read upside down
may enhance memory.
 Slamecka & Graf – compared generation
of synonyms and rhymes. Both improved
memory, but synonyms did more.

 Method of Loci – place items in a location,
then take a mental walk.
 Peg-word System – use peg words as a
structure and associate a list of items with
them using visualization.
 Create acronyms for lists of items.
 Convert nonsense syllables (DAX, GIB)
into meaningful items by associating them
with real words (e.g., DAD).

 http://www.youtube.com/watch?v=3cYf9vkW_xU
 http://www.totlol.com/watch/5d-6Q5V79CM/This-Old-Man/0/

1 – bun
2 – shoe
3 – tree
4 – door
5 – hive
6 – sticks
7 – heaven
8 – gate
9 – wine
10 -- hen

 It does not matter whether people intend
to learn something or not.
 What matters is how material is processed.
 Orienting tasks:
 Count whether work has e or g.
 Rate the pleasantness of words.
 Half of subjects told they would be asked to
remember words later, half not told.
 No advantage to knowing ahead of time.

 Self-reference effect -- people have better
memory for events that are important to
them and close friends.
 Flashbulb memories – recall of traumatic
events long after the fact.
 Seem vivid but can be very inaccurate.
 Thatcher’s resignation:
 60% memory for UK subjects, 20% non-UK

 Two explanations:
 People have special mechanisms for encoding
info relevant to themselves.
 Info relevant to the self is rehearsed more
often.
 High arousal may enhance memory.
 Memory is better for words related to the
self – perhaps due to better elaboration.

University of Southern Mississippi
Department of Psychology
Dr. David J. Echevarria, PhD
Spring 2008
david.echevarria@usm.edu
www.usm.edu/neurolab
Chapter 7 Memory

Chapter 6 is on learning
Chapter 7 is on memory
How is memory related to learning???

 Think about all the times in one day
you rely on your memory:
 When is my next class?
 Did I pay my rent?
 Where did I park my car?
 When is my boy/girl friend’s birthday?
 Performance on exams

 Tip of the tongue
 Did you ever say, “I can’t remember”
only to actually “remember” later on?
 How easily are they accessed?
 What can interfere with memory?

 Memory span: Number of items that
can be recalled from short-term
memory, in order, on half of the tested
memory trials
 It’s about 7 plus or minus 2 items
 Not absolute; also depends on:
 How quickly items can be rehearsed
 Chunking
▪ Rearranging incoming information into
meaningful or familiar patterns

 Several distinct mechanisms:
 Phonological loop: Like the inner voice; stores
word sounds
 Visuospatial sketchpad: Stores visual and
spatial information
 Central executive: Determines which
mechanism to use, coordinates among them
 Brain damage can selectively affect a
single mechanism

 How does information get into memory?
 How is information maintained in
memory?
 How is information pulled back out of
memory?

Figure 7.2 Three key processes in memory

 The role of attention
 Focusing awareness
 Selective attention = selection of input
 Filtering: early or late?

Figure 7.3 Models of selective attention

 Incoming information processed at
different levels
 Deeper processing = longer lasting
memory codes
 Encoding levels:
 Structural = shallow
 Phonemic = intermediate
 Semantic = deep

Figure 7.4 Levels-of-processing theory

Above is a scanpath of one reader over a broadsheet newspaper spread. The reader
turned pages in her own pace, and read the entire newspaper.
This is quite typical data. The texts are read no deeper than 40 % of their lengths.
Very short looks on photos and long looks on information graphics.
http://www.sol.lu.se/humlab/eyetracking/
Scanning a Scene

Figure 7.5 Retention at three levels of processing

 Elaboration = linking a stimulus to other
information at the time of encoding
 Thinking of examples
 Visual Imagery = creation of visual
images to represent words to be
remembered
 Easier for concrete objects: Dual-coding theory
 Self-Referent Encoding
 Making information personally meaningful

 Analogy: information storage in computers
~ information storage in human memory
 Information-processing theories
 Subdivide memory into 3 different stores
▪ Sensory, Short-term, Long-term

Figure 7.7 The Atkinson and Schiffrin model of memory storage

 Brief preservation of information in
original sensory form
 Auditory/Visual – approximately ¼
second
 George Sperling (1960)
▪ Classic experiment on visual sensory store

Figure 7.8 Sperling’s (1960) study of sensory memory

 Limited capacity – magical number 7
plus or minus 2
 Chunking – grouping familiar stimuli for
storage as a single unit
 Limited duration – about 20
seconds without rehearsal
 Rehearsal – the process of repetitively
verbalizing or thinking about the
information

Figure 7.9 Peterson and Peterson’s (1959) study of short-term memory

 STM not limited to phonemic encoding
 Loss of information not only due to decay
 Baddeley (1986) – 3 components of
working memory
 Phonological rehearsal loop
 Visuospatial sketchpad
 Executive control system

 Permanent storage?
 Flashbulb memories
 Recall through hypnosis
 Debate: are STM and LTM really different?
 Phonemic vs. Semantic encoding
 Decay vs. Interference based forgetting

 Clustering and Conceptual Hierarchies
 Schemas and Scripts
 Semantic Networks
 Connectionist Networks and PDP Models

 The tip-of-the-tongue phenomenon – a
failure in retrieval
 Retrieval cues
 Recalling an event
 Context cues
 Reconstructing memories
 Misinformation effect
▪ Source monitoring, reality monitoring

 Retention – the proportion of material
retained
 Recall
 Recognition
 Relearning
 Ebbinghaus’s Forgetting Curve

Figure 7.16 Ebbinghaus’ forgetting curve for nonsense syllables

Figure 7.17 Recognition versus recall in the measurement of retention

 Ineffective Encoding
 Decay theory
 Interference theory
 Proactive
 Retroactive

Figure 7.19 Retroactive and proactive interference

Figure 7.20 Estimates of the prevalence of childhood physical and sexual abuse

 Encoding Specificity
 Transfer-Appropriate Processing
 Repression
 Authenticity of repressed memories?
 Memory illusions
 Controversy

Figure 7.22 The prevalence of false memories observed by Roediger and McDermott (1995)

 Biochemistry
 Alteration in synaptic transmission
▪ Hormones modulating neurotransmitter systems
▪ Protein synthesis
 Neural circuitry
 Localized neural circuits
▪ Reusable pathways in the brain
▪ Long-term potentiation

 Anatomy
 Anterograde and Retrograde Amnesia
▪ Cerebral cortex, Prefrontal cortex, Hippocampus,
▪ Dentate gyrus, Amygdala, Cerebellum

Figure 7.23 The anatomy of memory

Figure 7.25 Retrograde versus anterograde amnesia

 Declarative vs. Procedural
 Semantic vs. Episodic
 Prospective vs. Retrospective

Figure 7.26 Theories of independent memory systems

 Engage in adequate rehearsal
 Distribute practice and minimize
interference
 Emphasize deep processing and transfer-
appropriate processing
 Organize information
 Use verbal mnemonics
 Use visual mnemonics

Chapter 25: Molecular Mechanisms of Learning and
Memory

 Neurobiology of memory
 Identifying where and how different types of
information are stored
 Hebb
 Memory results from synaptic modification
 Study of simple invertebrates
 Synaptic alterations underlie memories
(procedural)
 Electrical stimulation of brain
 Experimentally produce measurable synaptic
alterations - dissect mechanisms

 Procedural memories amenable to
investigation
 Nonassociative Learning
 Habituation
▪ Learning to ignore stimulus
that lacks meaning
 Sensitization
▪ Learning to intensify response
to stimuli

 Associative Learning
 Classical Conditioning: Pair an unconditional
stimulus (UC) with a conditional stimulus (CS)
to get a conditioned response (CR)

 Associative Learning (Cont’d)
 Instrumental Conditioning
▪ Learn to associate a response with a meaningful
stimulus, e.g., reward lever pressing for food
▪ Complex neural circuits related to role played by
motivation

 Experimental advantages in using
invertebrate nervous systems
 Small nervous systems
 Large neurons
 Identifiable neurons
 Identifiable circuits
 Simple genetics

 Gill-withdrawal reflex
 Habituation

 Nonassociative Learning in Aplysia (Cont’d)
 Habituation results from presynaptic modification at L7

 Repeated electrical stimulation of a sensory neuron leads to a
progressively smaller EPSP in the postsynaptic motor neuron

 Sensitization of the Gill-Withdrawal Reflex involves L29 axoaxonic
synapse

(Cont’d)
 5-HT released by L29 in response
to head shock leads to G-protein
coupled activation of adenylyl
cyclase in sensory axon terminal.
 Cyclic AMP production activates
protein kinase A.
 Phosphate groups attach to a
potassium channel, causing it to
close

(Cont’d)
 Effect of decreased potassium
conductance in sensory axon
terminal
 More calcium ions admitted into
terminal and more transmitter
release

 Associative Learning in Aplysia
 Classical conditioning: CS initially
produces no response but after
pairing with US, causes withdrawal

• The molecular basis for classical conditioning in Aplysia
– Pairing CS and US causes greater activation of adenylyl cyclase
because CS admits Ca2+ into the presynaptic terminal

 Neural basis of memory: principles
learned from invertebrate studies
 Learning and memory can result from
modifications of synaptic transmission
 Synaptic modifications can be triggered by
conversion of neural activity into intracellular
second messengers
 Memories can result from alterations in
existing synaptic proteins

 Cerebellum: Important site for motor learning
 Anatomy of the Cerebellar Cortex
▪ Features of Purkinje cells
▪ Dendrites extend only into molecular layer
▪ Cell axons synapse on deep cerebellar nuclei neurons
▪ GABA as a neurotransmitter

 The structure of the cerebellar cortex

• Cancellation of expected reafference in the electrosensory
cerebellum of skates- synaptic plasticity at parallel fiber
synapses.

(Cont’d)
 Mechanisms of cerebellar LTD
▪ Learning
▪ Rise in [Ca2+]i and [Na+]i and the activation of protein
kinase C
▪ Memory
▪ Internalized AMPA channels and depressed excitatory
postsynaptic currents

 Synaptic Plasticity in the Cerebellar Cortex (Cont’d)

 LTP and LTD
▪ Key to forming declarative memories in the brain
 Bliss and Lomo
▪ High frequency electrical stimulation of excitatory pathway
 Anatomy of Hippocampus
▪ Brain slice preparation: Study of LTD and LTP

 Anatomy of the Hippocampus

(Cont’d)
 Properties of LTP in CA1

 Synaptic Plasticity in the
Hippocampus (Cont’d)
 Mechanisms of LTP in CA1
▪ Glutamate receptors mediate
excitatory synaptic transmission
▪ NMDA receptors and AMPA
receptors

 Long-Term Depression in CA1

(Cont’d)
 BCM theory
▪ When the postsynaptic cell is
weakly depolarized by other inputs:
Active synapses undergo LTD
instead of LTP
▪ Accounts for bidirectional synaptic
changes (up or down)

(Cont’d)
 LTP, LTD, and Glutamate Receptor Trafficking
▪ Stable synaptic transmission: AMPA receptors are
replaced maintaining the same number
▪ LTD and LTP disrupt equilibrium
▪ Bidirectional regulation of phosphorylation

 LTP, LTD, and Glutamate Receptor Trafficking (Cont’d)

 LTP, LTD, and Memory
▪ Tonegawa, Silva, and colleagues
▪ Genetic “knockout” mice
▪ Consequences of genetic deletions (e.g., CaMK11 subunit)
▪ Advances (temporal and spatial control)
▪ Limitations of using genetic mutants to study LTP/learning:
secondary consequences

 Phosphorylation as a long term
mechanism:Persistently Active
Protein Kinases
 Phosphorylation maintained:
Kinases stay “on”
▪ CaMKII and LTP
▪ Molecular switch hypothesis

 Protein Synthesis
 Protein synthesis required for formation of long-
term memory
▪ Protein synthesis inhibitors
▪ Deficits in learning and memory
 CREB and Memory
▪ CREB: Cyclic AMP response element binding protein

 Protein Synthesis (Cont’d)
 Structural Plasticity and Memory
▪ Long-term memory associated with transcription
and formation of new synapses
▪ Rat in complex environment: Shows increase in
number of neuron synapses by about 25%

 Learning and memory
 Occur at synapses
 Unique features of Ca2+
 Critical for neurotransmitter secretion and
muscle contraction, every form of synaptic
plasticity
 Charge-carrying ion plus a potent second
messenger
▪ Can couple electrical activity with long-term changes
in brain

 The molecular basis for classical conditioning in Aplysia
 Pairing CS and US causes greater activation of adenylyl
cyclase because CS admits Ca2+ into the presynaptic terminal

 Associative Learning in Aplysia
 Classical conditioning: CS initially produces no response but after
pairing with US, causes withdrawal

 Synaptic Plasticity in Human area IT

LECTURE 20-21: CELLULAR BASIS OF LEARNING & MEMORY
REQUIRED READING: Kandel text, Chapter 63, and Assigned Review Articles
Research on cellular basis of learning & memory mainly performed in three animal systems
Aplysia Drosophila Mouse
All neurons and synapses
in behavioral circuits are
identified and can be recorded
easily
Ideal for detailing mechanisms
underlying implicit learned motor
responses
Capable of
learned behaviors
Amenable to random
mutagenesis and
selection of mutants
with defective
behaviors
Similar anatomy to human
Amenable to study of
explicit memory
Hippocampus amenable
to electrophysiology
Behavior modification of
genetically modified mice

APLYSIA SHORT-TERM LEARNED RESPONSES AFFECTING GILL WITHDRAWL REFLEX
HABITUATION SENSITIZATION CLASSICAL
CONDITIONING
Repeated tactile stimulation of
siphon
depresses
gill withdrawl response
Harmful stimulus
sensitizes
to subsequent
harmful OR harmless
stimuli given to
same OR different
body regions
Pairing harmful stimulus
with preceding harmless
conditioning stimulus sensitizes
to subsequent
conditioning stimulus
but not to tactile stimuli
given to other body areas

HABITUATION IS DUE TO DEPRESSED NEUROTRANSMITTER RELEASE AT SEVERAL SITES
Rapidly repeated tactile stimulation of siphon
attenuates gill withdrawl both during the
training and for a short period afterwards.
Habituation is due to reduced
neurotransmitter release by the
sensory neuron and by relevant interneurons
in response to the tactile stimulus.
I.e., the memory of habituation
is distributed at various synapses
in the circuit
Whereas a rapid series of stimuli induces
short-term habituation,
several sets of tactile stimuli distributed
over several hours induces
long-term habituation that lasts for weeks.

SHORT-TERM SENSITIZATION IS MEDIATED THROUGH AXO-AXONIC
SEROTONERGIC SYNAPSES OF FACILITATING INTERNEURONS
Serotonergic facilitating interneurons
send axo-axonic connections to
broadly distributed sensory neurons
Unconditioned stimulus causes
interneurons to release serotonin,
which acts through metabotropic
HT receptors to increase the
likelihood of neurotransmitter release
following sensory neuron firing
Sensitization can be mimicked without
sensitizing stimulus by local
experimental application of serotonin
Sensitization is mediated by
presynaptic elevation of
cAMP & PKA activity,
which has three effects:
1) Greater proportion of vesicles

CLASSICAL CONDITIONING EMPLOYS SEQUENCE-REINFORCED PRODUCTION OF cAMP
Conditioning is only effective when CS precedes US by a short interval (~ 0.5 se
CS elevates calcium in presynaptic terminal at moment of US.
Calcium/CAM enhances the enzymatic activity of adenylate cyclase triggered by
Adenylate cyclase is a biochemical “coincidence detector”

TEMPORALLY SPACED SENSITIZATION OR CONDITIONING TRAININGS
INDUCE LONG-TERM IMPLICIT MEMORY
Long-term sensitization
and conditioning are
also mediated through
presynaptic cAMP
production
and PKA activity
PKA induces specific
CREB-dependent
gene transcription and
protein synthesis:
Newly synthesized
ubiquitin
hydrolase degrades
PKA regulatory subunits,
making the enzyme
constitutively active
Other newly synthesized

GENETIC SCREENS FOR GENES AFFECTING CONDITIONING IMPLICIT MEMORY
ALL AFFECT THE cAMP-PKA-CREB PATHWAY
FLY MUTANTS SELECTED FOR DEFECTS IN IMPLICIT MEMORY
DUNCE encodes cAMP phosphodiesterase
RUTABAGA mutant defective for Ca+2/CAM enhancement of cyclase
AMNESIAC encodes a peptide neurotransmitter acting on GS-coupled rec
PKA-R1 encodes PKA

HIPPOCAMPAL NEURONS IN DIFFERENT RELAYS ARE ALL
CAPABLE OF UNDERGOING SYNAPTIC LONG-TERM POTENTIATION
AXON STIMULATION PROTOCOL AMPLITUDE OF EPSCS
20 min1 m 60 min
EPSPSlope(%original)
300
100
200
TIME (min)
6020 40 80“THETA” BURST
One Theta burst gives what is sometimes c
Early LTP,
which is less than doubling
of EPSC which lasts for hours
Four Theta bursts spaced minutes apart ge
Late LTP,
with up to 4-fold EPSC stimulation
that lasts for days

INDUCTION AND EXPRESSION OF SYNAPTIC PLASTICITY
Prior synaptic activity can INDUCE long-term plasticity. Such plasticity can be IND
molecular events occuring either presynaptically or postsynaptically.
The changes in transmission following synaptic plasticity can be EXPRESSED eith
presynaptically and/or postsynaptically, and need not correspond to the site of IN
E.g., at a certain synapse, postsynaptic calcium influx can INDUCE plasticity which
EXPRESSED as changes in presynaptic neurotransmitter release probability.

LTP AT MOSSY FIBER--CA3 SYNAPSES IS DUE TO PRESYNAPTIC CALCIUM INFLUX
AND cAMP/PKA PATHWAY

LTP AT SCHAFFER COLLATERAL--CA1 SYNAPSES IS DUE TO
POSTSYNAPTIC CALCIUM INFLUX AND CAM KINASE ACTIVITY
LTP at CA3-CA1 synapse is blocked by
NMDAR antagonist APV and by inhibitors
of CAM kinase

PRESYNAPTIC COMPONENT OF EARLY AND LATE LTP AT
CA3--CA1 SYNAPSES RESEMBLES SHORT- AND LONG-TERM SENSITIZATION
Late LTP
absolutely requires
new protein synthesis

PRESYNAPTIC COMPONENT OF EARLY AND LATE LTP REQUIRES
POSTSYNAPTIC CAMK ACTIVITY AND RETROGRADE SIGNALS

OTHER MECHANISMS OF PLASTICITY ENHANCING EPSPS
LTP can be expressed postsynaptically as a reduction of leak conductance in dend
This enables the EPSC to generate EPSP with greater length and time constants
Excitatory transmission can be enhanced by HETEROSYNAPTIC INHIBITION OF
TRANSMISSION. This is mediated by endogenous cannabinoids acting on pre
terminals of nearby GABAergic synapses.

IS LTP REQUIRED FOR HIPPOCAMPAL CONSOLIDATION OF EXPLICIT MEMORY?
CAMK AND NMDAR1 NEEDED FOR LONG-TERM SPATIAL REPRESENTATION IN HIPPOCAMPU
Single pyramidal neuron
in hippocampus
fires when mouse is in
certain location
(independent of
animal’s orientation)
Normal mouse remembers
where it has been.
spatial map in HC
does not change in
subsequent chamber trials

IS LTP REQUIRED FOR HIPPOCAMPAL CONSOLIDATION OF EXPLICIT MEMORY?
HIPPOCAMPAL CAMK AND NMDAR1 NEEDED FOR BOTH LTP AND SPATIAL MEMORY

SYNAPSES SENSITIVE TO NMDAR-MEDIATED LTP ARE ALSO SENSITIVE
TO NMDAR-MEDIATED LONG-TERM DEPRESSION (LTD)
AXON STIMULATION PROTOCOL AMPLITUDE OF EPSCS
20 min1 m 60 min
EPSPSlope(%original)
300
100
200
TIME (min)
6020 40 80
LTP
20 min5 m 60 min
EPSPSlope(%original) 300
100
200
TIME (min)
6020 40 80
LTD

LTD HAS A LOWER CALCIUM CONCENTRATION THRESHOLD THAN LTP,
BUT LTP IS DOMINANT
LOW-FREQUENCY STIMULUS TRAIN
LOW-LEVEL CALCIUM ENTRY
ACTIVATION OF CALCINEURIN
AMPA RECEPTOR INTERNALIZATION
THETA- OR HIGH-FREQUENCY STIMULU
GREATER CALCIUM ENTRY
ACTIVATION OF CALCINEURIN AND CAM
AMPA RECEPTOR INSERTION AND PHO

STRUCTURAL AND FUNCTIONAL FEATURES OF AMPA-TYPE GLUTAMATE RECEPTORS
AMPA receptors are homo- or hetero-tetramers
Restriction of calcium entry mediated by GluR2; tetramers containing >1 GluR2 subunit co
AMPA receptors encoded by different genes or by alternative splicing have different C-term
Receptor tails contain phosphorylation sites for different protein kinases and binding sites
for PDZ-domain-containing proteins
Receptors containing only GluR2(short) and/or GluR3 subunits are delivered constitutively
vesicles to synapse
Retention at synapse mediated by complex with Glutamate Receptor Interacting Protein (G

NMDAR-INDUCED CAMK ACTIVITY ACTS ON AMPA RECEPTORS IN TWO WAYS
TO PROMOTE LTP
CAMK
PDZ-protein
STG
GRIP
PSD-95
GRIP
PSD-95
Calcineurin
CAMK phosphorylates an unknown
protein, enabling a PDZ-protein
that interacts with long tail
on GluR1 to deliver receptor
TO EXTRASYNAPTIC SITE
Delivered receptors migrate (randomly?)
into post-synaptic density,
where interactions of receptor-
associated GRIP and STG and the
major postsynaptic matrix protein
PSD-95 anchor receptor to synapse
Newly delivered GluR1-containing
AMPA receptors can be phosphorylated
directly by CAMK, which
increases unitary conductance
Calcineurin activation promotes internalization
of AMPA receptors containing only
short-tail subunits, thereby promoting LTD
WHEN HIGH CALCIUM ENTRY ACTIVATES BOTH CALCINEURIN AND CAMK
CAMK-MEDIATED GluR1-CONTAINING AMPAR EXOCYTOSIS EXCEEDS CAL
SHORT TAIL-ONLY AMPAR ENDOCYTOSIS

HIGH CAMK ACTIVITY INDUCED DURING LATE LTP IS ALSO MEDIATED BY
NEW CAM KINASE PROTEIN SYNTHESIS NEAR THE SYNAPSE
Most mRNAs have 3’ polyA tail, which is necessary for initiation of the mRNA’s translatio
Neurons contain some mRNAs that are not polyadenylated, are not translated,
and are transported along dendrites to areas near dendritic spines
NMDA receptor activation and calcium entry activates a protein kinase
called AURORA
Aurora kinase activates translation of nearby dormant mRNAs
ONE OF THESE DORMANT RNAs ENCODES CAM KINASE
Because of its dendritic localizaation, new CAMK synthesis is restricted to the synapse u
The dendritic localization of dormant CAMK RNA and its activation during LTP are media
Cytoplasmic Polyadenylation Element Binding (CPEB) protein

HOW DOES CPEB PROTEIN CONTROL RNA DORMANCY AND ACTIVATION IN NEURONS?
PolyA is needed for assembly of 5’
translation initiation complex
CPEB protein binding to 3’ CPE
helps mask RNA 5’ end
CPEB phosphorylation by Aurora allows for recruitment of polyA polye
Polyadenylation of dormant RNA allows assembly of 5’ translation initia

 The strange case of
Charles D’Sousa
 Or is it Philip Cutajar?
 Rare type of disorder
 Some stuff clearly
spared
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.

 Results with amnesiacs has lead to many
discoveries about memory
 Episodic vs. semantic memory
 Procedural vs. declarative memory
 Implicit vs. explicit memory
 Phonological loop vs. visuo spatial sketchpad

 Taxonomy
 Individual differences
 Interpretation
 Application
 Mostly comes down to a lack of control,
which of course is inevitable

 We pretty much have to rely on these
 They are, thankfully, rare
 Usually some sort of accident or a stroke

 Stroke patient
 Both Medial temporal lobes, left Hp and
lots of surrounding area, but not the
amygdala
 Had trouble naming objects
 Anterograde and retrograde amnesia
 Similar to KC

 Case of encephalitis
 Pervasive amnesia
 Both semantic and
episodic impairment
 Temporal lobe dilation
 Hp destroyed
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.

 Retrograde amnesia
 Losing past memories
 Anterograde amnesia
 No new memories
 Spared function
 Often implicit tasks, such as priming or ability
to learn a new skill

 Working Memory
 Semantic memory
 Even KC could learn new stuff
 Declarative information using Tulving’s
method
 Restrict errors

 Difficulties in interference, retrieval and
encoding
 Consolidation
 Tends to come down to something to do with
HP
 Context or sending item off for processing or
some such thing

 What is a cat?
 Temporal lobe problems
 Oddly enough, episodic memory often
intact in these rare cases

 There are cases of people with intact
phonological loops and visuo spatial
sketchpads that are pretty much toast
 And vice versa

 More than half of all
dementia is from AD
 2 times more
women than men
 Could be because
women live longer
though
 dementia and brain
stuff
 Neurofibrillary
tangles and neuritic
plaques

 MASSIVE cell death
 In essence, you get like lesions
everywhere
 ‘cortical’ dementia, but you get these
lesions, holes really, everywhere

 ACh is important in memory, especially in
HP
 The ACh system is severely damaged in
AD
 Indeed it is almost targeted
 Other systems too though

 Episodic effects
 Eventually semantic effects
 Retrieval cues don’t help
 Information was not even encoded
 Nondeclarative stuff, skills etc, are the last
to go

 Most drugs target the cholinergic system
 This disease not only affects the victim,
but also his/her family
 NGF is promising
 Treatments will come, but, reversal, I
dunno
 Respite care is key for the family

 Frankly there is not a great deal of hope
for most amnesiacs
 That said, neuroscience is moving pretty
fast
 Has helped us understand normal function

The information-processing
model of human memory

Relations between iconic memory, short-
term memory and long-term memory

Logie’s (1995) drawing of the
components of working memory
Source: Adapted from Logie, R., Visual Spatial Working Memory, p. 127. © 1995. Reprinted by permission of Psychology
Press Limited, Hove, UK.

The limits of short-term and
working memory
Source: (a) Adapted from Peterson, L.M. and Peterson, J.M., Short-term retention of individual verbal items. Journal of
Experimental Psychology, 1959, 58, 193–198., (b) Adapted from Waugh, N.C. and Norman, D.A., Primary memory.
Psychological Review, 1965, 72, 89–104.

Shallow versus deep
processing
Source: Based on Craik, F.I.M. and Lockhart, R.S., Levels of processing: A framework for memory research. Journal of
Verbal Behavior, 1972, 11, 671–684.

Explicit versus implicit
memory
Source: Based on data from Graf, P. and Mandler, G., Activation makes words more accessible, but not necessarily more
retrievable. Journal of Verbal Learning and Verbal Behavior, 1984, 23, 553–568.

Ebbinghaus’s forgetting curve
Source: Adapted from Ebbinghaus, H., Memory: A contribution to experimental psychology (H.A. Ruger and C.E. Bussenius,
trans.), 1885/1913. Teacher’s College Press, Columbia University, New York.

Eyewitness testimony
Source: Based on data from Loftus, E.F. and Palmer, J.C., Reconstruction of automobile destruction: An example of the
interaction between language and memory. Journal of Verbal Learning and Verbal Behavior, 1974, 13, 585–589.

Retroactive and proactive
interference

Explicit and implicit memory of amnesic
and non-amnesic individuals
Source: Adapted from Graf, P., Squire, L.R. and Mandler, G., The information that amnesic patients do not forget. Journal of
Experimental Psychology: Learning, memory and cognition, 1984, 10, 164–178.

The effect of hippocampal damage on a
rat’s navigational ability
Source: Morris, R.G.M. et al., Place navigation impaired in rats with hippocampal lesions. Nature, 1982, 182(297), 681–683.
Reprinted with permission from Nature. © 1982 Macmillan Magazines Limited.

Spatial navigation
Source: Maguire, E.A., Frackowiak, R.S.J. and Frith, C.D., Recalling routes around London: Activation of the right
hippocampus in taxi drivers. Journal of Neuroscience, 1997, 17, 7103. © Society for Neuroscience.

 Encode information into memory traces (stored
bits of memory)
 Process information and put into memory
storage
 Use retrieval to recall and output information
when needed

• Information-processing approach: mind
functions like a sophisticated computer
• Unlike computers, human minds have the
capacity for consciousness
▪ Awareness of one’s own thoughts and the
external world
▪ Focusing attention brings stimulus into
consciousness

 Explicit memory
 Conscious use of memory
 Searching memory for stored information
 Implicit memory
 Access and retrieve memories without
conscious effort

 Sensory memory
 Information comes into sensory organs, stored
briefly in sensory form
 Short-term memory
 Temporary holding tank for limited amounts of
information
 Long-term memory
 Permanent storage of memories

 Information received from sense organs lasts for
short period of time
 Acquire information primarily from sight (iconic
memory) and hearing (echoic memory), but also
through other senses (haptic memory)
 Transfer occurs when we pay attention to
sensory input to move it from iconic memory to
short-term memory

 Temporary holding tank
 Utilizes dual-coding system
 Memories stored visually or acoustically
 Limited capacity and duration

 George Miller
 Average person holds about 7 + 2 items in STM
 Phone numbers, social security numbers, etc.
 Chunking can help increase capacity
 Grouping information into meaningful units
 Number of chunks that can be held decreases
as chunks get larger

 Once passed into STM, information can only be
kept for 30 seconds without some type of
processing
 Maintenance rehearsal
 Repetition of material in short-term memory

 Maintenance rehearsal produces a weak transfer
into LTM
 Elaborative rehearsal
 Forming associations, or mental connections,
between information in STM to information
already stored in LTM

 Fergus Craik and Robert Lockhart
 The more thoroughly or deeply you process
information, the stronger the transfer to LTM
 Both maintenance and elaborative rehearsal
allow for transfer to LTM, but elaborative
rehearsal involves a deep level of processing
 Difference between simply repeating material
and thinking about material
 Pays off in terms of storage and retrieval of
information

 LTM is where information is stored for long
periods of time
 Limitless capacity
 Capacity problems are likely related to lack of
focus or lack of space in STM or working
memory

 Encoding—how we break down the
information coming into our senses
 Storage—keeping memories in our long
term memory
 Retrieval—process in which information in
your memory can be recalled

 Encoding occurs in several forms
 Acoustic (sound), visual, semantic
 Semantic encoding is most common
 Stores general meaning, rather than all
sensory details
 Encode and connect new information with
already stored information in LTM

 Schemata – generalized knowledge structures
 Filing systems for knowledge about particular
concepts
 Default values for missing information
 Various types of schemata
 Object, abstract concept, person
 Stereotypes
 Scripts

 Declarative memory – explicit memory for
knowledge easily verbalized (e.g. names, dates)
 Two parts of declarative memory
 Semantic memory – concepts
 Episodic memory – memory for events
▪ Also called autobiographical memory
▪ Memories have personal awareness

 Females betters able to recall emotional
childhood memories
 Females tend to organize autobiographical
memories in more diverse categories (i.e. more
elaborative processing)

 Memory that is not readily put into words -
procedures for skills such as riding a bike, tying
shoe, etc.
 Often is implicit memory (unconscious)
 Tends to last longer than declarative memory
 Studies from people with amnesia suggest that
procedural memory is a separate memory
system

 Retrieval – act of moving information from LTM
back to working memory or consciousness
 Probe or cue sent in search of stored memory
traces
 Recall task – probe relatively weak and does not
contain much cue information (e.g. essay
question)
 Recognition task – probe stronger, contains
more cue information (e.g. multiple choice
question)
 Memory must be available and accessible

 Pay attention, minimizing distractions
 Do not cram for exams
 Distributed is better than massed practice
 Use elaborative rehearsal
 Use overlearning
 Use mnemonic devices
 Acronyms (APA), acrostics(rhyme or saying)
▪ Remember the major functions of memory: Ellen
stopped remembering (encoding, storage, retrieval)

 Flashbulb memories – detailed memories of
emotionally charged events
 These memories are not always accurate
 Store gist of information in LTM, not exact
details
 Examples of flashbulb memories:
▪ Attacks on 9/11
▪ Assassination of JFK
▪ Birth of child
▪ Wedding

 Elizabeth Loftus
 Eyewitness memory can be manipulated by
expectations
 Memories can be permanently altered by things
that happen after we encode memories (false
memories)
 False memories become part of memory of
original event

Chapter 9
Memory
James A. McCubbin, PhD
Clemson University
Worth Publishers

 Memory
 persistence of learning over time
via the storage and retrieval of
information
 Flashbulb Memory
 a clear memory of an
emotionally significant moment
or event

 Memory as Information Processing
 similar to a computer
 write to file
 save to disk
 read from disk
 Encoding
 the processing of information into the
memory system
 i.e., extracting meaning

 Storage
 the retention of encoded information
over time
 Retrieval
 process of getting information out of
memory

 Sensory Memory
 the immediate, initial recording of
sensory information in the memory
system
 Working Memory
 focuses more on the processing of
briefly stored information

 Short-Term Memory
 activated memory that holds a few
items briefly
 look up a phone number, then quickly
dial before the information is forgotten
 Long-Term Memory
 the relatively permanent and limitless
storehouse of the memory system

External
events
Sensory
memory
Short-term
memory
Long-term
memory
Sensory input
Attention to important
or novel information
Encoding
Encoding
Retrieving

 Automatic Processing
 unconscious encoding of incidental
information
 space
 time
 frequency
 well-learned information
 word meanings
 we can learn automatic processing
 reading backwards

 Effortful Processing
 requires attention and conscious
effort
 Rehearsal
 conscious repetition of information
 to maintain it in consciousness
 to encode it for storage

 Ebbinghaus used nonsense
syllables
 TUV ZOF GEK WAV
 the more times practiced on Day 1,
the fewer repetitions to relearn on
Day 2
 Spacing Effect
 distributed practice yields better long-
term retention than massed practice

20
15
10
5
0
8 16 24 32 42 53 64
Time in
minutes
taken to
relearn
list on
day 2
Number of repetitions of list on day 1

12
Percent
age of
words
recalled
0
90
80
70
60
50
40
30
20
10
Position of
word in list
1 2 3 4 5 6 7 8 9 10 11
Serial Position Effect--
tendency to recall
best the last items in
a list

 Semantic Encoding
 encoding of meaning
 including meaning of words
 Acoustic Encoding
 encoding of sound
 especially sound of words
 Visual Encoding
 encoding of picture images

 Imagery
 mental pictures
 a powerful aid to effortful processing,
especially when combined with semantic
encoding
 Mnemonics
 memory aids
 especially those techniques that use vivid
imagery and organizational devices

 Chunking
 organizing items into familiar, manageable
units
 like horizontal organization--1776149218121941
 often occurs automatically
 use of acronyms
 HOMES--Huron, Ontario, Michigan, Erie, Superior
 ARITHMETIC--A Rat In Tom’s House Might Eat
Tom’s Ice Cream

 Organized information is more easily recalled

 Hierarchies
 complex information broken down into broad concepts and
further subdivided into categories and subcategories
Encoding
(automatic
or effortful)
Imagery
(visual
Encoding)
Meaning
(semantic
Encoding)
Organization
Chunks Hierarchies

 Iconic Memory
 a momentary sensory memory of visual
stimuli
 a photographic or picture image memory
lasting no more that a few tenths of a
second
 Echoic Memory
 momentary sensory memory of auditory
stimuli

 Short-Term
Memory
 limited in
duration and
capacity
 “magical”
number 7+/-2
0
10
20
30
40
50
60
70
80
90
3 6 9 12 15 18
Time in seconds between presentation
of contestants and recall request
(no rehearsal allowed)
Percentage
who recalled
consonants

 How does storage work?
 Karl Lashley (1950)
 rats learn maze
 lesion cortex
 test memory
 Synaptic changes
 Long-term Potentiation
 increase in synapse’s firing potential after brief, rapid
stimulation
 Strong emotions make for stronger memories
 some stress hormones boost learning and retention

 Amnesia--the loss of memory
 Explicit Memory
 memory of facts and experiences that one can
consciously know and declare
 also called declarative memory
 hippocampus--neural center in limbic system that
helps process explicit memories for storage
 Implicit Memory
 retention independent of conscious recollection
 also called procedural memory

Types of
long-term
memories
Explicit
(declarative)
With conscious
recall
Implicit
(nondeclarative)
Without conscious
recall
Facts-general
knowledge
(“semantic
memory”)
Personally
experienced
events
(“episodic
memory”)
Skills-motor
and cognitive
Dispositions-
classical and
operant
conditioning
effects

 MRI scan of hippocampus (in red)
Hippocampus

 Recall
 measure of memory in which the
person must retrieve information
learned earlier
 as on a fill-in-the blank test
 Recognition
 Measure of memory in which the
person has only to identify items
previously learned
 as on a multiple-choice test

 Relearning
 memory measure that assesses
the amount of time saved when
learning material a second time
 Priming
 activation, often unconsciously,
of particular associations in
memory

0
10
20
30
40
Water/
land
Land/
water
Water/
water
Different contexts for
hearing and recall
Same contexts for
hearing and recall
Land/
land
Percentage of
words recalled

 Deja Vu (French)--already seen
 cues from the current situation may subconsciously
trigger retrieval of an earlier similar experience
 "I've experienced this before."
 Mood-congruent Memory
 tendency to recall experiences that are consistent with
one’s current mood
 memory, emotions, or moods serve as retrieval cues
 State-dependent Memory
 what is learned in one state (while one is high, drunk, or
depressed) can more easily be remembered when in same
state

 After learning to move
a mobile by kicking,
infants had their
learning reactivated
most strongly when
retested in the same
rather than a different
context (Butler &
Rovee-Collier, 1989).

 Forgetting as encoding failure
 Information never enters the long-term
memory
External
events
Sensory
memory
Short-
term
memory
Long-
term
memory
Attention
Encoding
Encoding
Encoding
failure leads
to forgetting

 Forgetting as
encoding failure
 Which penny is the
real thing?

 Ebbinghaus
forgetting
curve over
30 days--
initially
rapid, then
levels off
with time
12345 10 15 20 25 30
10
20
30
40
50
60
0
Time in days since learning list
Percentage of
list retained
when
relearning

 The forgetting curve for Spanish learned in school
Retention
drops,
then levels off
1 3 5 9½ 14½ 25 35½ 49½
Time in years after completion of Spanish course
100%
90
80
70
60
50
40
30
20
10
0
Percentage of
original
vocabulary
retained

 Forgetting can result from failure to
retrieve information from long-term
memory
External
events
Attention
Encoding
Encoding
Retrieval failure
leads to forgetting
Retrieval
Sensory
memory
Short-term
memory
Long-term
memory

 Learning some items may disrupt
retrieval of other information
 Proactive (forward acting) Interference
 disruptive effect of prior learning on recall of
new information
 Retroactive (backwards acting)
Interference
 disruptive effect of new learning on recall of
old information

 Retroactive Interference
Without interfering
events, recall is
better
After sleep
After remaining awake
1 2 3 4 5 6 7 8
Hours elapsed after learning syllables
90%
80
70
60
50
40
30
20
10
0
Percentage
of syllables
recalled

 Forgetting can
occur at any
memory stage
 As we process
information,
we filter, alter,
or lose much
of it

 Motivated Forgetting
 people unknowingly revise memories
 Repression
 defense mechanism that banishes from
consciousness anxiety-arousing thoughts,
feelings, and memories

 We filter information and fill in
missing pieces
 Misinformation Effect
 incorporating misleading information into
one's memory of an event
 Source Amnesia
 attributing to the wrong source an event
that we experienced, heard about, read
about, or imagined (misattribution)

 Eyewitnesses
reconstruct
memories when
questioned
Depiction of actual accident
Leading question:
“About how fast were the cars
going when they smashed into
each other?”
Memory
construction

 Memories of Abuse
 Repressed or Constructed?
 Child sexual abuse does occur
 Some adults do actually forget such episodes
 False Memory Syndrome
 condition in which a person’s identity and
relationships center around a false but strongly
believed memory of traumatic experience
 sometimes induced by well-meaning therapists

 Most people can agree on the following:
 Injustice happens
 Incest happens
 Forgetting happens
 Recovered memories are commonplace
 Memories recovered under hypnosis or drugs
are especially unreliable
 Memories of things happening before age 3
are unreliable
 Memories, whether false or real, are upsetting

 Study repeatedly to boost recall
 Spend more time rehearsing or
actively thinking about the material
 Make material personally
meaningful
 Use mnemonic devices
 associate with peg words--something
already stored
 make up story
 chunk--acronyms

 Activate retrieval cues--mentally
recreate situation and mood
 Recall events while they are fresh--
before you encounter misinformation
 Minimize interference
 Test your own knowledge
 rehearse
 determine what you do not yet
know

 EVOLUTION: CHANGE (in behavior)THROUGH TIME.
 DESCENT WITH MODIFICATION: THE MODE OF EVOLUTION BY
BRANCHING COMMON DESCENT.
 GRADUALISM: CHANGE (in behavior) IS SLOW, STEADY, STATELY.
NATURA NON FACIT SALTUS. GIVEN ENOUGH TIME EVOLUTION CAN
ACCOUNT FOR THE ORIGIN OF NEW SPECIES.
 MULTIPLICATION OF SPECIATION: EVOLUTION PRODUCES NOT JUST
NEW SPECIES (behavior), BUT AN INCREASING NUMBER OF NEW SPECIES
(behaviors).
 NATURAL SELECTION: THE MECHANISM OF EVOLUTIONARY CHANGE
CAN BE SUBDIVIDED INTO FIVE STEPS: (SEE NEXT SLIDE).

 1. POPULATIONS [behaviors] TEND TO INCREASE INDEFINITELY IN A
GEOMETRIC RATIO. [FROM OBSERVATION]
 2. IN A NATURAL ENVIRONMENT, HOWEVER, POPULATION [behavior]
NUMBERS STABILIZE AT A CERTAIN LEVEL. [FROM OBSERVATION]
 THERE MUST BE A “STRUGGLE FOR EXISTENCE” SINCE NOT ALL
ORGANISMS [behaviors] PRODUCED CAN SURVIVE. [FROM INFERENCE]
 THERE IS VARIATION IN EVERY SPECIES [behaviors]. [FROM
OBSERVATION]
 IN THE STRUGGLE FOR EXISTENCE, THOSE VARIATIONS THAT ARE
BETTER ADAPTED TO THE ENVIRONMENT LEAVE BEHIND MORE
OFFSPRING THAN THE LESS WELL ADAPTED INDIVIDUALS, ALSO KNOWN
AS DIFFERENTIAL REPRODUCTIVE SUCCESS. [FROM INFERENCE]

 PRINCIPLES OF LEARNING SHOULD APPLY EQUALLY TO DIFFERENT
BEHAVIORS AND TO DIFFERENT SPECIES OF ANIMALS
 LEARNING PROCESSES CAN BE STUDIED MOST OBJECTIVELY WHEN
THE FOCUS OF STUDY IS ON STIMULI AND RESPONSES.
 INTERNAL PROCESSES ARE LARGELY EXCLUDED FROM SCIENTIFIC
STUDY
 LEARNING INVOLVES A BEHAVIOR CHANGE
 ORGANISMS ARE BORN AS BLANK SLATES (tabula rasa).
 LEARNING IS LARGELY THE RESULT OF ENVIRONMENTAL EVENTS.
 THE MOST USEFUL THEORIES TEND TO BE PARSIMONIOUS ONES.

Concept Map:
Behavioral Approaches

SOCIAL COGNITIVE
APPROACHES TO
LEARNING
Bandura’s Social
Cognitive Theory
Evaluating the
Social Cognitive
Approaches
Cognitive
Behavior
Approaches
Observational
Learning

 Bandura’s social cognitive theory
 Social cognitive theory
 Reciprocal determinism model
 Self-efficacy

B
Behavior
P/C
Person and
cognitive factors
E
Environment

 Observational learning
 What is observational learning?
 The classic Bobo doll study
 Bandura’s contemporary model of
observational learning
▪ Attention
▪ Retention
▪ Motor reproduction
▪ Reinforcement of incentive conditions

 Cognitive behavior approaches and self-
regulation
 Cognitive behavior approaches
▪ Self-instructional methods

 Self-regulatory learning
▪ A model of self-regulatory learning
Self-Evaluation
and Monitoring
Putting a Plan into
Action and Monitoring It
Goal Setting and
Strategic Planning
Monitoring Outcomes
and Refining Strategies

 Goal Setting
 Planning
 Self-motivation (intrinsic motivation)
 Attention control
 Application of learning strategies
 Self-monitoring
 Self-evaluation
 Self-reflection

 Some Learning Processes may be unique to human beings.
 Cognitive processes are the focus of study.
 Objective, systematic observations of people’s behavior should
be the focus of scientific inquiry; however, inferences about
unobservable mental processes can often be drawn from
behavior.
 Individuals are actively involved in the learning process.
 Learning involves the formation of mental representations or
associations that are not necessarily reflected in overt behavior
changes.

 Cognitive processes influence learning.
 As children grow, they become capable of
increasingly more sophisticated thought.
 People organize the things they learn.
 New information is most easily acquired when
people can associate it with things they have
already learned.
 People control their own learning.

 Jean Piaget (French)
 Lev Vygotsky (RUSSIAN)
 Edward Tolman (American)
 Jerome Bruner (American)
 Kurt Lewin (German)

Kurt Lewin (From Alfred Marrow’s book)
BH = f (P+E)

B
A
R
R
I
E
R
G
O
A
L
R
E
G
I
O
N
PSYCHOLOGICAL LIFE SPACE
PERSON
NEEDS
ABILITIES
-
+
FOREIGN HULL VECTORS
VALENCES

Concept Map:
Chapter Eight Overview

Characteristics of the
Information-Processing
Approach
THE COGNITIVE
INFORMATION-
PROCESSING
APPROACH
Exploring the
Information-Processing
Approach

 Exploring the information-processing
approach
 Cognitive psychology

 Characteristics of the information-processing
approach
 Thinking
 Change mechanisms
▪ Encoding
▪ Automaticity
▪ Strategy construction
▪ Transfer
 Self-modification
▪ Metacognition

MEMORY
What is
Memory?
Retrieval and
Forgetting
StorageEncoding

 What is memory?
ENCODING
Getting
information
into memory
STORAGE
Retaining
information
over time
RETRIEVAL
Taking
information
out of storage

 Encoding
 Rehearsal
 Deep processing
▪ Levels of processing theory
 Elaboration
 Constructing images
 Organization
▪ Chunking

 Storage
 Memory’s time frames
▪ Sensory memory
▪ Short-term (working) memory
▪ Memory span
▪ Long-term memory

Teresa M. McDevitt, Jeanne Ellis Ormrod
Child Development and Education
Copyright ©2002 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
I Sensation and Perception
II Attention
A. Distractibility decreases; sustained attention increases
B. Attention becomes increasingly purposeful
III Working Memory
A. Processing speed increases
B. Children acquire more effective cognitive processes
C. The physical capacity of working memory
may increase somewhat
IV Long-Term Memory
A. The amount of knowledge stored in long-term
memory increases
B. Knowledge becomes increasingly symbolic in nature

Atkinson and Shiffrin’s Theory of
Memory

Visuospatial
scratchpad
Central
executive
Articulatory
loop

Long-term memory
Nondeclarative
(implicit)
Declarative
(explicit)
Episodic memory Semantic memory

 Storage
 Content knowledge and how it is represented
in long-term memory
▪ Content knowledge
▪ Network theories
▪ Schema theories
▪ Schema
▪ Script

 Retrieval and forgetting
 Retrieval
▪ Serial position effect
▪ Primacy effect
▪ Recency effect
▪ Encoding specificity principle
▪ Recall
▪ Recognition

 Retrieval and forgetting
 Forgetting
▪ Cue-dependent forgetting
▪ Interference theory
▪ Decay theory

 Perspectives on motivation
 The humanist perspective
▪ Maslow’s hierarchy of needs
▪ Physiological
▪ Safety
▪ Love and belongingness
▪ Esteem
▪ Self-actualization

Memory - Form and function

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