PSY 368 Human Memory

PSY 368 Human Memory

Neuropsychology & MemoryReview 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 (video clip # 19, ~7mins)

• Cortical, progressive dementia• Disease is associated with the development of

neuro-fibrillary 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 • 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.

Preclinical AD


• Alzheimer’s disease • 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.

Mild to Moderate AD


• Alzheimer’s disease • 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.

Severe ADs


• The brains of people with AD have an abundance of two abnormal structures:

An actual AD plaque

An actual AD tangle

• Beta-amyloid plaques

• Dense deposits of protein and cellular material that accumulate outside and around nerve cells

• Neurofibrillary tangles

• Twisted fibers that build up inside the nerve cell

• 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.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

SHALLOW

DEEP

Craik and Tulving (1975)

Levels of Processing

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.

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”?.



Encoding: Recognition test:

Rhyming test:

Does ____ rhyme with legal? (eagle)

63% 49%

Does ____ have feathers? (eagle)

84% 33%

Morris, Bransford, and Franks (1977)

• 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.


Encoding: Recognition test:

Rhyming test:

Does ____ rhyme with legal? (eagle)

63% 49%

Does ____ have feathers? (eagle)

84% 33%

Morris, Bransford, and Franks (1977)

• 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.

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

Encoding Specificity Principle

Thompson and Tulving (1970)

• Thompson and Tulving showed that this can be reversed if you change the study context.

• 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.

Mem

ory

Perf

orm

an

ce

Rapid forgetting for short delays - slower for longer delays

Forgetting

Ebbinghaus (1885)

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.

Bahrick, Bahrick & Wittlinger (1975)

Permastore

• 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

Bahrick, Bahrick & Wittlinger (1975)

Permastore

• Tested nearly 400 high-school graduates on their ability to recognize and name classmates after delays of up to 30 years.Results were mixed:

• Relatively unimpaired:• Ability to recognize their classmates’

faces/names. • Ability to match up names to the

appropriate portraits.

Conclusion:• Recall, but not recognition, of well-learned personal material,

closely follows the forgetting curve first demonstrated by Ebbinghaus (1913).

• Extensively impaired:• Ability to recall a name, given a person’s

portrait.

RecognitionName Matching

RecallName the picture

3.3 mons. 47+ yrs.

• Retroactive Interference (RI)

How do we forget?

• 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.

• Proactive Interference (PI)

How do we forget?

• 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

indirect direct

incidentalimplicit memoryexpts.

Levels of Processing

expts.

intentional? explicit

memoryexpts.

Test Instructions

Study Instruction

s

Implicit Memory: Often defined as "memory without awareness”

• Also “Non-declarative” & “procedural” (Squire, Knowlton, & Mesen, 1993)

Perceptual TasksWord identification

Word stem completion

Word fragment completion

Degraded word naming

Anagram solution

Lexical decision

Implicit Memory Tasks

Non-Verbal Tasks

Picture fragment naming

Object decision task

Possible/impossible object decision

Conceptual TasksWord association

Category instance generation

Answering general knowledge questions

Often defined as "memory without awareness”

• 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

Mixing Measures

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

• 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)

Jacoby (1991)

Process Dissociation Procedure

Multiple Memory Systems

• What is a system?

Schacter and Tulving (1994)System Other Name Subsystems Characteristics

Procedural Nondeclarative Motor skills Non-conscious operation(indirect)

Cognitive skills

Simple conditioning

Simple associative learning

Perceptual representation

Nondeclarative Visual word form

Auditroy word form

Structural description

Primary memory

Working memory Visual Conscious operation(direct)

Auditory

Semantic Generic Spatial

Factual Relational

Knowledge

Episodic Personal

Autobiographical

Event memory

If you “know how to do something”

Allows you to automatically recognize things

See earlier in the semester

Factual information (chpt 10)Memory of events

• Goal to demonstrate• data-driven processing can affect direct tests• data-driven processing do not necessarily

affect indirect tests

Blaxton (1989)

Transfer Appropriate Process

Data-driven Conceptually-driven

Direct Graphic-cuedRecall

Free Recall

Indirect FragmentCompletion

GeneralKnowledge

Target word: bashful• graphic-cued recall: looks like “bushful”• free recall• frag completion: b_sh_u_• General knowledge: “Name one of the 7 dwarfs”

Blaxton (1989)



Free Recall


GeneralKnowledge


S’s saw or heard lists of words (key IV here)

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

Blaxton (1989)




Free Recall


GeneralKnowledge

Same pattern of results regardless of modality

Visual better than auditory for both

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

Blaxton (1989)




Free Recall


GeneralKnowledge

Visual should be better than auditory

Visual and auditory should be about the same

ResultsPriming Effect (V > A) for

data-driven tasks only:

• indirect: frag completion

• direct: graphemic-cued recall

Not all indirect tests display priming effect.

• Gen Know (indirect, conceptual): V = A

Blaxton (1989)


ConclusionsSupport view that

processing rather than system is what is important

• 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

Methods of Study

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)

• 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

Other Crucial Parts

Structure of the brain

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

• Thus, there are four possible outcomes:

• Hits• Correctly reporting the presence of the signal

• Correct Rejections• Correctly reporting the absence of the signal

• 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

CORRECT

INCORRECT

• 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

How does Recognition work?

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


(Tulving , 1985; Gardiner, 1988)

Relatively recent change in recognition methodologyDoes 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”

Remember versus Know Process Model

• 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

• Generation effect• R: G > R• K: R = G

• Word frequency effect• R: L > H• K: H = L

• Evidence for special ability:(1)Prosopagnosia(2)Newborn preferences(3)Face inversion effect(4)Pop-out effect for faces

Face Recognition

Documents

PSY 368 Human Memory