Transcript lecture 16 - Illinois State University Department of Psychology

PSY 368 Human
Memory
Neuropsychology & Memory
Review for Exam 2
Announcements
• Focus Questions for Weldon and Roediger (1987)
Due Monday Today
• Exam 2 Wednesday (March 28)
Alzheimer’s Disease
• Alzheimer’s disease
• Cortical, progressive dementia
• Criteria
• deficit in two or more areas of cognition, at least one of
which is memory
• interferes with social or occupational functioning
• decline from premorbid level
• gradually progressive course
• rule out other causes
Alzheimer’s Disease
• Alzheimer’s disease (video clip # 19, ~7mins)
• Cortical, progressive dementia
• Disease is associated with the development of neurofibrillary tangles and plaques
• To stay healthy, neurons must
communicate with each other, carry
out metabolism, and repair
themselves.
• AD disrupts all three of these
essential jobs.
Pet Scan of
Normal Brain
Pet Scan of Alzheimer’s
Disease Brain
Alzheimer’s Disease
• Alzheimer’s disease
Preclinical AD
• Signs of AD are first noticed in the
entorhinal cortex, then proceed to the
hippocampus.
• Affected regions begin to shrink as
nerve cells die.
• Changes can begin 10-20 years before
symptoms appear.
• Memory loss is the first sign of AD.
Alzheimer’s Disease
• Alzheimer’s disease
Mild to Moderate AD
• AD spreads through the brain. The
cerebral cortex begins to shrink as more
and more neurons stop working and die.
• Mild AD signs can include memory loss,
confusion, trouble handling money, poor
judgment, mood changes, and increased
anxiety.
• Moderate AD signs can include increased
memory loss and confusion, problems
recognizing people, difficulty with
language and thoughts, restlessness,
agitation, wandering, and repetitive
statements.
Alzheimer’s Disease
• Alzheimer’s disease
Severe ADs
• In severe AD, extreme shrinkage
occurs in the brain. Patients are
completely dependent on others for
care.
• Symptoms can include weight loss,
seizures, skin infections, groaning,
moaning, or grunting, increased
sleeping, loss of bladder and bowel
control.
• Death usually occurs from aspiration
pneumonia or other infections.
Caregivers can turn to a hospice for
help and palliative care.
Alzheimer’s Disease
• Alzheimer’s disease
• The brains of people with AD have an abundance of
two abnormal structures:
• Beta-amyloid plaques
• Dense deposits of protein and
cellular material that accumulate
outside and around nerve cells
An actual AD plaque
• Neurofibrillary tangles
• Twisted fibers that build up inside
the nerve cell
An actual AD tangle
Alzheimer’s Disease
• Alzheimer’s disease
• Relatively intact articulatory loop of WM
• three types of memory problems
•
•
•
•
WM – verbal and spatial memory impairments
Episodic memory impaired (e.g., free recall)
Executive function
Semantic memory is also impaired
• Naming and word generation impaired in AD
• Note: pure amnesics do not have the latter two impairments
Exam 2 Review
• Chapter 5: Memory Processing
• Chapter 6: Forgetting
• Chapter 7: Implicit Memory
• Chapter 8: Neuropsychology and Memory
• Chapter 9: Recognition
Exam 2 Review
• Chapter 5: Memory Processing
• Craik & Lockhart (1972), Levels of processing (slide 16)
• Craik & Tulving (1975) – good experimental evidence
supporting LOP (deeper processing remembered better) (slide 17)
• Transfer Appropriate Processing
• Morris, Bransford, & Franks (1977) – good experimental
evidence supporting TAP (match of processing at encoding and
retrieval more important than LOP) (slide 18-21)
• Context effects (similar context at encoding & test, better
memory)
• Encoding Specificity Principle (Thompson & Tulving, 1970)
(slide 22-23)
Exam 2 Review
• Chapter 6: Forgetting
•
•
•
•
Ebbinghaus and forgetting function (slide 24)
Permastore (see Bahrick studies) (slides 25-27)
Retrospective vs. Prospective memory
Theories of forgetting
•
•
•
•
Failure of Consolidation
Decay
Context/cue mismatch
Interference (retroactive and proactive) (slides 28-29)
Exam 2 Review
• Chapter 7: Implicit Memory
• Implicit memory tasks (vs. explicit tasks) (slides 30-31)
• Process Dissociation Procedure (Jacoby, 1991) (slides 32-34)
• Theoretical accounts
• The activation view
• Multiple memory systems (slide 35)
• Transfer appropriate processing
• Blaxton (1989) (data vs. conceptual driven, or direct vs.
indirect) (slides 36-40)
• Bias view
Exam 2 Review
• Chapter 8: Neuropsychology and Memory
• Methods of study (slide 41)
• Neurons and the Brain (slides 42-45)
• Hippocampus
• Memory Disorders
• Amnesia (slide 46)
• Anterograde
• retrograde
• Alzheimer’s Disease (today’s lecture, slides 3-9)
Exam 2 Review
• Chapter 9: Recognition
• Recall vs. Recognition
• Signal Detection Method (slide 47)
• Single vs. dual process theories (slides 48-51)
•
•
•
•
Tagging Model
Strength Theory
Generate-Recognize Model
Remember/Know Processes Model
• Face Recognition (slide 52)
Level of Processing
Craik & Lockhart (1972)
• Considered level of processing at study to be more important for
memory than intent to learn
• Levels of processing = how “deeply” the item is processed
• The depth of processing helps determine the durability in LTM.
SHALLOW
DEEP
Level of Processing
Example
1) Visual Form
“DOG” includes the letters D, O,
and G
2) Phonology
Rhymes with FOG
3) Semantics
(Meaning)
A four-legged pet that often chases
cats and chews on bones
Levels of Processing
Craik and Tulving (1975)
Task:
• Participants viewed words and were asked to make three
different types of judgments:
• Visual processing (e.g. “Is LOG in upper case?” Y/N)
• Phonological (e.g. “Does DOG rhyme with LOG?” Y/N)
• Semantic (e.g. “Does DOG fit in the sentence: ‘The ___ chased
the cat’?” Y/N)
• Finally, participants were asked to recognize the words they
had seen before in a surprise test including both old and new
words.
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
• Task:
• Participants made either a phonological or semantic judgment
about each item on a word list.
• Study: eagle (yes/no fits clue)
• Deep - The ____ is the US national bird.
• Shallow - rhymes with legal
• The learning was incidental: participants were not told that they
would have to later recall the words.
• This constrains (limits) the learning strategies used.
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
• Task:
• The final test was either:
• A standard recognition test for the learned words.
• A rhyming recognition test for learned words
• e.g., Was a word presented that rhymed with “regal”?.
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
Encoding:
Recognition Rhyming test:
test:
Does ____ rhyme 63%
with legal?
(eagle)
49%
Does ____ have
84%
feathers? (eagle)
33%
• Results:
• Standard recognition test: Deeper processing led to better performance.
• Rhyming recognition test: The shallower rhyme-based encoding task led
to better performance because it matched the demands of the testing
situation.
Transfer-appropriate processing
Morris, Bransford, and Franks (1977)
Encoding:
Recognition Rhyming test:
test:
Does ____ rhyme 63%
with legal?
(eagle)
49%
Does ____ have
84%
feathers? (eagle)
33%
• Conclusion:
• The take-home message is that when the processing at encoding
matches the processing at retrieval, performance will be better.
• It only makes sense to talk about a learning method’s efficiency in
the context of the type of final test.
Encoding Specificity Principle
Thompson and Tulving (1970)
• Examined effectiveness of cue
• Had people learn lists of strong or weak associates.
• Strong vs. weak cues (“flower”)
• Strong: bloom
• Weak: fruit
• Study: no cue vs. weak cue
• Test: no cue, weak cue, or strong cue
Encoding Specificity Principle
Thompson and Tulving (1970)
• The best retrieval cue for a word like “flower” would be a
strong associate like “bloom.” “fruit” is weakly associated to
“flower,” and would be unlikely to pull it out.
0.9
0.8
0.7
0.6
Memory 0.5
Accuracy 0.4
0.3
0.2
0.1
0
No cue
Weak cue
No cue
Weak cue
Test Cue
Strong cue
• Thompson and
Tulving showed that
this can be reversed if
you change the study
context.
Forgetting
Memory
Performance
Ebbinghaus (1885)
Rapid forgetting for short
delays - slower for longer
delays
What do we forget?
• Permastore:
• Describes the leveling off of the forgetting curve at long delays.
• Beyond this point, memories appear impervious to further
forgetting.
Bahrick (1984)
• Permastore
• Rapid forgetting of foreign
language for 3 yrs,
• Then of a asymptotes (levels off)
after about 2 years,
• Stays fairly constant even up to 50
yrs.
• The overall level of retention is
determined by the level of initial
learning.
Permastore
Bahrick, Bahrick & Wittlinger (1975)
• Tested nearly 400 high-school graduates on their ability to recognize
and name classmates after delays of up to 30 years.
• Questions
• Recall
• Can you list all your classmates?
• Can you name all these faces?
• Recognition
• Is this the name of a classmate?
• Is this the face of a classmate?
• Match these names and faces
Permastore
Bahrick, Bahrick & Wittlinger (1975)
• Tested nearly 400 high-school graduates on their ability to recognize
and name classmates after delays of up to 30 years.
Recognition
Name Matching
Results were mixed:
100
Percent Correct
90
• Relatively unimpaired:
80
70
• Ability to recognize their classmates’
60
50
faces/names.
40
30
Recall
• Ability to match up names to the
20
Name the picture
appropriate portraits.
10
0
3.3 mons.
47+ yrs.
• Extensively impaired:
Time since Graduation
• Ability to recall a name, given a person’s portrait.
Conclusion:
• Recall, but not recognition, of well-learned personal material, closely follows
the forgetting curve first demonstrated by Ebbinghaus (1913).
How do we forget?
• Retroactive Interference (RI)
• Forgetting caused by encoding new traces into memory in
between the initial encoding of the target and when it is tested.
• Introducing a related second list of items impairs recall of the first
list compared to a control condition.
How do we forget?
• Proactive Interference (PI)
• The tendency for older memories to interfere with the retrieval of
more recent experiences and knowledge.
• The number of previous learning experiences (e.g. lists) largely
determines the rate of forgetting at long delays.
Memory Tasks
Test Instructions
incidental
Study
Instructions
intentional
indirect
direct
implicit
memory
expts.
Levels of
Processing
expts.
?
explicit
memory
expts.
Implicit Memory: Often defined as "memory without
awareness”
• Also “Non-declarative” & “procedural” (Squire, Knowlton, &
Mesen, 1993)
Implicit Memory Tasks
Often defined as "memory without awareness”
Perceptual Tasks
Word identification
Word stem completion
Non-Verbal Tasks
Picture fragment
naming
Word fragment completion Object decision task
Possible/impossible
Degraded word naming
object decision
Anagram solution
Lexical decision
Conceptual Tasks
Word association
Category instance
generation
Answering general
knowledge questions
Mixing Measures
• Tasks are not “process pure” (Jacoby, 1991)
• Indirect measures of memory may be “contaminated” by
intentional uses of memory
• E.g., in stem completion task, subjects might remember items
from previous list and use them to complete the stems
• Direct measures may be influenced by unconscious or
automatic influences (Jacoby, Toth, & Yonelinas, 1993)
• Process-Dissociation Procedure was developed to separate
automatic (unconscious) and conscious processes
Process Dissociation Procedure
Jacoby (1991)
• Read a list of words – List 1
• Hear a list of words – List 2
• Two recognition tests:
• Both tests include List 1, List 2 and novel words.
• Inclusion = complete task with studied or any item
• Respond “old” if word was on either list.
• Exclusion = complete task with item NOT studied (exclude
studied items)
• Respond “old” only if word was on List 2.
Process Dissociation Procedure
Jacoby (1991)
• Can calculate C and A for each condition in the
experiment
• C = (Proportion of studied items in inclusion) (Proportion of studied items in exclusion)
• A = (Proportion of studied items in exclusion) / (1-C)
• The C and A values are estimated as proportions - values
between 0 and 1.0
• Data
• Proportion of studied items in inclusion = C + (1-C)(A)
• Proportion of studied items in exclusion = (1-C)(A)
Multiple Memory Systems
Schacter and Tulving (1994)
• What is a system?
If you “know how to do
something”
System
Other Name
Subsystems
Characteristics
Procedural
Nondeclarative
Motor skills
Non-conscious
operation
(indirect)
Cognitive skills
Simple
conditioning
Simple associative
learning
Allows you to automatically
recognize things
Perceptual
representation
Nondeclarative
Visual word form
Auditroy word
form
Structural
description
See earlier in the semester
Factual information
(chpt 10)
Primary
memory
Working memory
Semantic
Generic
Spatial
Factual
Relational
Auditory
Knowledge
Memory of events
Episodic
Visual
Personal
Autobiographical
Event memory
Conscious
operation
(direct)
Transfer Appropriate Process
Blaxton (1989)
• Goal to demonstrate
• data-driven processing can affect direct tests
• data-driven processing do not necessarily affect indirect
tests
Data-driven
Conceptually-driven
Direct
Graphic-cued
Recall
Free Recall
Indirect
Fragment
Completion
General
Knowledge
Transfer Appropriate Process
Blaxton (1989) S’s saw or heard lists of words (key IV here)
Target word: bashful
•
•
•
•
graphic-cued recall: looks like “bushful”
free recall
frag completion: b_sh_u_
General knowledge: “Name one of the 7 dwarfs”
Data-driven
Conceptually-driven
Direct
Graphic-cued
Recall
Free Recall
Indirect
Fragment
Completion
General
Knowledge
Transfer Appropriate Process
Blaxton (1989)
Predictions
• Systems view: modality match should affect only indirect
tests (if indirect tap separate system, then modality should
affect them in the same way)
• for both implicit tests: visual > auditory
• for both explicit test: visual = auditory
Data-driven
Conceptually-driven
Direct
Graphic-cued
Recall
Free Recall Same pattern of results
regardless of modality
Indirect
Fragment
Completion
General
Visual better than auditory
Knowledge
for both
Transfer Appropriate Process
Blaxton (1989)
Predictions
• TAP View: modality match should affect data-driven tasks
only. (priming depends on match between study/test
processing match & not on indirect vs direct):
• for both data-driven tests: visual > auditory
• for both conceptually-driven tests: visual = auditory
Data-driven
Direct
Indirect
Conceptually-driven
Graphic-cued
Free Recall
Recall
Visual
should
Fragment
General
Completion be better Knowledge
than
auditory
Visual and
auditory
should
be about
the same
Transfer Appropriate Process
Blaxton (1989)
Results
Priming Effect (V > A) for datadriven tasks only:
• indirect: frag completion
• direct: graphemic-cued recall
Not all indirect tests display
priming effect.
• Gen Know (indirect,
conceptual): V = A
Conclusions
Support view that processing
rather than system is what is
important
Methods of Study
• Neuroscientists typically study memory in animals
• Can record electrical or chemical signals directly from
individual neurons, or carefully remove small portions of
the brain
• Psychologists typically study memory in humans
• More limited techniques
• “Experiments of nature” Case studies
• Lesions
• Direct electrical stimulation
• Neuroimaging techniques
The Neuron
•
•
•
•
•
•
•
Dendrites
Cell body
Axon
Myelin sheath
Terminal buttons
Synapse
Billions of synapses
nice reference web page
Neurons and Memory
Hebbian Learning:
• Cells that fire together
wire together
•
•
•
Connections between
neurons are weighted
Weights can be
changed based on
feedback from later
cells
Basic assumption of most
computational neural
network models
(connectionism)
Structure of the brain
Other Crucial Parts
• Limbic system: controls emotions and
instinctive behavior (includes the hippocampus
and parts of the cortex)
• Thalamus: receives sensory and limbic
information and sends to cerebral cortex
• Hypothalamus: monitors certain activities and
controls body’s internal clock
• Hippocampus: where short-term memories are
converted to long-term memories
Hippocampus
• Important for formation of new episodic memories
• Important for encoding perceptual aspects of memories
• Novel events, places, and stimuli
• Important for declarative memory
• Especially as part of medial temporal lobe
• Supported by case of HM
• Video (location, 1 min)
• Video (damage, 7 mins)
Amnesia
• Loss of memory ability - usually due to lesion or
surgical removal of various parts of the brain
• Relatively spared performance in other domains
• A pure amnesia is relatively rare
• Two broad categories:
• Retrograde: loss of memories for events prior to damage
• Anterograde: loss of ability to store new memories of events
after damage
Signal Detection Theory
• Recognition accuracy depends on:
• Whether a signal (noise/target memory) was actually
presented
• The participant’s response
CORRECT
Thus, there are four possible outcomes:
• Hits
• Correctly reporting the presence of the signal
• Correct Rejections
• Correctly reporting the absence of the signal
INCORRECT
•
• False Alarms
• Incorrectly reporting presence of the signal when it
did not occur
• Misses
• Failing to report the presence of the signal when it
occurred
How does Recognition work?
• Two classes of theories
• Single process theories - retrieval is one process
regardless of task
• Dual process theories - two processes needed for
retrieval - can be task dependent
Dual-process theories
Generate-recognize model (G-R)
• Recall is made up of two processes
• First, generate a set of plausible candidates for recall (Generation
stage)
• Second, confirm whether each word is worthy of being recalled
(Recognition stage – not the same as the recognition test)
• Recognition is made up of only one process
• Because the experimenter provides a candidate, recognition does
not need the generation stage
Dual-process theories
 Remember versus Know Process Model
(Tulving , 1985; Gardiner, 1988)
Relatively recent change in recognition methodology
Does someone
 Specifically remember
 Conscious recollection of the information’s occurrence at study
 Just somehow know
 Knowing that it was on the list, but not having the conscious
recollection, just a “feeling of knowing”
Dual-process theories
• Remember/Know processes
• Make R/K judgment for “Old” items
• Remember = consciously recollect details of the item’s
presentation
• Know = sure an item was presented, but can’t recall any of the
details of presentation
• R/K differ by:
• Picture superiority
effect
• R: P > W
• K: W > P
• Word frequency
effect
• R: L > H
• K: H = L
• Generation
effect
• R: G > R
• K: R = G
Face Recognition
• Evidence for special ability:
(1)
(2)
(3)
(4)
Prosopagnosia
Newborn preferences
Face inversion effect
Pop-out effect for faces