Topic #5: Memory & Intelligence

Created by Martin R. Cox

Adapted from presentation package by Dean Richards

Introductory Psychology Lecture Presentation Series

Copyright 1999 by Allyn and Bacon All rights reserved.

Processes of Memory

RetrievalEncodingPut into memory

Storage

Recover from memory

Hold in memory

Atkinson-Shiffrin Model

Environment

Short Term

Memory Retrieval

Elaboration Long Term

MemorySensing

Sensory Memory

Attention

LossLoss

Sensory Memory

• Visual sensory memory (the icon) • Auditory sensory memory (the echo) • Probably others as well

– Very large capacity– Very short duration:

• about 250 ms. for the icon• 1-2 sec. for the echo

Short Term Memory (STM)• Limited capacity -- 7 plus or minus 2

chunksChunk: a meaningful unit

Examples: • A single letter (S)• A group of letters (FBI)• A group of words (Four score and seven years ago)

• Duration of 20-30 sec., due to limited capacity & interference

Short Term Memory

STM Storage• Increases with age

• Primarily due to increases in chunking ability with age

• Often phonetic

• Things that sound the same interfere with each other

Displacement in STM

cheeseeggspeassyrupapplesflourmilk

eggspeassyrupapplesflourmilkbread

peassyrupapplesflourmilkbread

syrupapplesflourmilkbread

applesflourmilkbread

flourmilkbread

milkbreadbread

STM(7 slots) Lost from

STM

bread

Long Term Memory (LTM)• Huge capacity• Potentially long duration (decades)• Organized by meaning

• Nondeclarative Memory (implicit memory): Memory for motor skills learned through practice (procedural memory) and responses learned through classical conditioning.

• Declarative Memory (explicit memory): Memory for facts & personal experiences

Declarative Memory

• EpisodicMemory:Memory for personal events

• SemanticMemory:Memory for common knowledge &

meaning

Remembering New Facts

• Easier for subjects you already know a lot about

• Difference probably due to opportunity for elaboration (relating, forming associations, imageries, organization, etc.)

• Elaborative rehearsal involves relating the new information to what you have already known.

Latent Memory%

Lat

er R

ecal

led

Judgement RequiredLetter Size Phonetic Meaning

Measuring Memory

Three measures typically used:

Recognition

Recall

Relearning

Recall Memory

• Remembering in the absence of the item being remembered

• Usually the most difficult test

Recognition Memory

• Recognizing material when it is seen

• Often, but not always, easier than recall

Relearning

• Assessed by comparing time needed to relearn material to initial learning time

• May be the most sensitive test

Forgetting

Rate of forgetting:

• fastest right after initial learning

• slower for more meaningful material

Forgetting

Causes:• Failure to Encode• Consolidation Failure• Decay• Interference• Motivated Forgetting• Retrieval Failure

Forgetting• Failure to Encode: Failing to put material into

LTM; Common in "forgetting" people's names

• Consolidation Failure: Loss due to organic disruption while the memory trace is being formed

• Decay: Fading of memory through disuse; Impossible to distinguish from permanent retrieval failure

Forgetting• Interference: Confusion or entanglement of similar

memories

• Motivated Forgetting: Repression of memories, usually to avoid dealing with traumatic experiences. Suppression of memories occur at a conscious level, deliberately not to remember an unpleasant event.

• Retrieval Failure: Inability to find the necessary memory cue for retrieval; Sometimes temporary (tip-of-the-tongue phenomenon)

Tip of the Tongue

• The feeling of being on the verge of recalling something

• Often you can say what letter it starts with, or how many syllables it has

Reconstruction

Piecing memory together from a few highlights, then filling in details based on what we think should have happened

Schemas

A schema is a general, stereotypical description of a highly familiar place or event (mall, fast-food restaurant, school, classroom, etc.)Schemas:

(a) help guide our actions,(b) help guide our memory,(c) may distort our perception and memory.

Eye Witness Testimony

• Relies greatly on reconstructive memory

• Influential in trials

• Accuracy is variable

Witness beliefs about their own testimony over time

Confidence

Accuracy

Low

er

Time

Hig

her

Expertise

• Experts remember more details

• Probably due to use of elaborative encoding

Hypnosis

• Increases rememberer's confidence & amount of inaccurate information

• Doesn't increase memory accuracy

Factors Affecting Retrieval

• Serial Position

• Environmental Context

• State-Dependence

• Stress and Anxiety

Serial Position Effect:Primacy Effect

• First items in a list are remembered better than items in the middle

• Probably due to greater odds of getting into long-term memory

Serial Position Effect: Recency Effect

• The last items in a list are remembered better than items in the middle, if tested immediately

• Probably due to their still being in STM

Environmental Context

• Becomes encoded along with the material being remembered

• Reinstating context often increases memory

State-Dependent Memory

• Internal body states are encoded with memories

• Memories easier to retrieve when these body states are entered again

Stress and MemoryPe

rform

ance

StressLow Moderate High

Biology and Memory

• The hippocampus forms long-term declarative memories, important for transferring information from STM to LTM

• The frontal lobesImportant to recall of episodic memories

The Hippocampus

Deep in the brain

The Frontal Lobe

Patient H.M.

Became unable to form new memories after surgical removal of the hippocampus

Patient K.C.

• Cannot remember anything that ever happened to him

• His semantic memory is unimpaired

Organic Memory Loss

• Unlike psychogenic amnesia, most recent memories lost first

• Earlier memories often retained

Improving Memory

• Organization

• Spaced Practice

• Overlearning

• Recall practice (Reciting)

• Mnemonic devices

Improving Memory

• Organization: Memory greatly enhanced by actively organizing material as it is learned

• Spaced Practice: Shorter practice sessions spaced widely apart; more effective than massed practice

Improving Memory

• Overlearning: Practicing material well beyond the point needed to recall it for the moment

• Recall Practice (Reciting): Practicing recalling material rather than just rereading it; Especially useful for college material

Improving Memory

• Mnemonic Devices:

– Strategies that can increase memory, esp. for material that is not easily organized;

– Impose an artificial structure on items that would otherwise be hard to remember

Mnemonic Devices

• Method of LociInvolves pairing each thing to be remembered with one of an organized set of familiar locations

• The Peg-Word MethodConnecting each thing to be remembered in an interactive image with each item on a standard listExample list: One is a bun, two is a shoe, ...

Mnemonic Devices

• Acronyms:Representing each item with a single letter

that fits into a familiar word or phrase

Example: "all cars eat gas" for the spaces in the bass clef