Long-Term Memory

Dr. Claudia J. StannyEXP 4507

Memory & Cognition

Spring 2009

Overview

• Types of Long Term Memory• Relation between encoding and retrieval• Encoding processes and their

consequences• Retrieval strategies• Autobiographical memory

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Long Term Memory: Ebbinghaus (1885) Long-term Retention Functions

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Types of Long Term Memory

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Distinctive Characteristics of LTMOrganization of information

• Schemas

Capacity

Duration• Bahrick: permastore

Encoding – impact on retention

Retrieval mechanisms• Forgetting: availability versus accessablity

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Encoding Strategies: Levels of Processing

Craik & Lockhart (1972)Orienting tasks assigned at study to induce

different levels of processing• Shallow processing (physical features of stimuli)

Does the word contain an E or a G?Is the word presented in capital or lower case letters?

• Intermediate processingWrite down a word that begins with the same sound.

• Deep processing (semantic encoding)Rate words on your perception of their PLEASANTNESS (1 = UNPLEASANT 7 = PLEASANT)

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Recognition performance for words processed at different levels

Data from EXP 3082 (2002) 7Claudia J. Stanny

Variations on Deep Processing

What kinds of processing “count” as deep processing?

Distinctive encoding• Encoding differs or makes a stimulus stand out• Isolation effects; unique encodings

Elaborate encoding• Create a code that includes multiple aspects• Complex codes; many connections to other

representations

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Self-Reference Effect

Processing task:

Does this word relate to you?

Recognition performance is as good as for a semantic processing task

Biggest improvement seen when participants think the word does apply to them (46%) than when it does not (34%)

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Generation EffectSlamecka & Graf (1978)

What is the effect of processing depth when you generate the code yourself versus when you have the coding given to you?

Read Condition• Shallow: SAVE – CAVE• Deep: SEA – OCEAN

Generate Condition• Shallow: SAVE – C____ (rhyme) CAVE• Deep: SEA – O_____ (synonym) OCEAN

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Encoding Specificity

Match between cues encoded at study and cues available during retrieval

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Emotion, Mood and Memory

Pollyanna Principle

Rate of forgetting for pleasant & unpleasant events

Mood-dependent congruence

Mood-dependent memory (encoding specificity)

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Retrieval from LTM

Types of Retention Tasks

Explicit Memory Tasks• Aware that memory is being used/tested• Subjective experience of intentional use of

memory

Implicit Memory Tasks• Task is perceived as a problem-solving task or

other cognitive challenge

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Comparing Memory Tasks

Explicit Memory TasksRecall

Cued recall

Recognition tests

yes/no recognition

multiple choice tests

Implicit Memory TasksWord completion task

V__L__A__E

Word stem completion task

OC __ __ __

Repetition priming (RT tasks)

Lexical decision task

Anagram solving

LVGEALI → _______

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Evidence for different types of LTM

Dissociation of performance on explicit and implicit memory tasks

Variables improve performance on explicit memory but do not influence implicit memory performance• Depth of processing

Variables improve implicit memory performance but do not influence explicit memory• Benefits of number of repetitions

Note: some variables have the same effect on both types of task (proactive interference)

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Effect of LOP on performance on an implicit and an explicit memory task

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Shallow processing task• Does the word have a B

or a P?

Deep processing task• Rate the word on its

pleasantness (1 – 7)

Implicit memory test• Anagram task

Explicit memory test• Free recall Data: EXP 4507L Spring 2006

Amnesia

Differences in performance by amnesiacs on implicit and explicit memory tasks

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How do experts differ from novices?Amount of knowledge in area of expertiseQuality of organization of information in LTM

• More efficient encoding of new information• More successful retrieval of information

Differences in cognitive strategies used• Chunking and organization of new material• Identifying distinctive characteristics of stimuli• Procedures used to solve problems

Better metacognition about processing• Judgments about task difficulty• Monitoring progress on a problem

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Expertise is Context-SpecificExpertise emerges from extensive deliberate

practice in a particular domain• 10 years of deliberate practice required (Ericsson, 2003)

Expertise in one domain does not make one an expert in every domain• Superior memory performance in one area of

expertise does not generalize to superior memory performance in general

• Problem identification and efficient solution is also domain-specific

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Autobiographical Memory

Special case of episodic memory

Memory for events of our personal life

Interaction with semantic memory:• Role of schemas in autobiographical recall• Consistency bias

Source monitoring• Identifying the origin of a memory or belief

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Recall of autobiographical memories across the life span (Rubin, 1997)

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Reminiscence Bump

Infantile Amnesia

Forgetting Function

Flashbulb MemoriesHighly detailed episodic memories of an eventContain many autobiographical details

• Source information for the news of the event• Detailed contextual information

Where you were, what you were doing, who you talked to, what your emotional response was, etc.

Are flashbulb memories special?Do they include errors seen in other memories?Are they subject to forgetting like other memories?

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Eyewitness Memory

Estimator Variables• Characteristics of the witness or witnessed event known to

have an influence on accuracy of witness recollections

System Variables• Characteristics of the legal / investigative process known

to have an influence on accuracy of witness recollections

Variables that produce memory distortions• Misleading questioning• Post-Information effects

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Factors that influence the accuracy of eyewitness memoryDelays between the event and recallIntrusions related to misinformationReconstructive nature of memory

Schema-based intrusions

Social pressure Demand characteristics of questioning the encourage

production of more information or a specific answer

Positive feedback following identifications during lineups increases confidence without increasing accuracy

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