MODELS OF MEMORY

DEFINITION OF MEMORY:

“The retention of learning or experience”

MEMORY

MEMORY ANALOGIES Library Aviary Underground map Computer STAGES OF MEMORY ENCODING STORAGE RETRIEVAL

MEMORY

THE SHORT TERM MEMORY DEFINITION: “Memory for events in the present or

immediate past” CAPACITY OF THE STM The Digit Span Test (Jacobs 1887) Magic number 7 (Miller 1956) Note: Vogel and Cowan (2001) have concluded its

more likely to be 4 items Chunking ( a useful application of psychological

theory) rehearsal

THE SHORT TERM MEMORY

ENCODING IN THE STM Predominantly acoustic (sound) Evidence = errors made with similar

sounding letters when presented visually for 0.75 seconds (Conrad 1964)

Note: research has shown we use other forms of coding also e.g. visual

DURATION OF THE STM Approx. 15 – 30 seconds without rehearsal

THE SHORT TERM MEMORY

A STUDY INTO THE DURATION OF THE STM (Peterson & Peterson 1959)

See worksheet

THE LONG TERM MEMORY

DEFINITION: “Memory for events that have happened in the past”

CAPACITY OF THE LTM Unknown Unlimited

THE LONG TERM MEMORY

ENCODING IN THE LTM Predominantly semantic Evidence: (Baddeley 1966) semantically similar

words presented to the LTM are most susceptible to being muddled up

But also acoustic, visual,

olfactory, gustatory DURATION OF THE LTM Potentially a lifetime but there

are many individual differences

THE MULTI-STORE MODEL OF MEMORY

(Atkinson & Shiffrin 1968) DIAGRAM

New idea of sensory memoryShort term and long term memories are permanent, structural components

SUPPORTING EVIDENCE (mini experiment)

1. PRIMACY/RECENCY EFFECT(Murdock1962)

The above diagram is called a serial position curve and is produced when a word list is free recalled.

PRIMACY EFFECT = RECENCY EFFECT =

2. DIFFERENT TYPES OF CODING IN STM & LTM

Baddeley (1966) studied STM P’s presented with acoustically similar words P’s then presented with semantically similar

words Results = immediate recall of acoustically

similar words was poor because the grammatical and phonemic parts of language are quickly forgotten

3. USE OF DIFFERENT AREAS OF THE BRAIN

• Using brain scans Beardsley 1997 found that people use the prefrontal cortex when doing a STM task and the hippocampus when doing a LTM task

4. STUDIES OF PEOPLE WITH MEMORY LOSS

See video and worksheet

EVALUATING THE MULTI-STORE MEMORY

POSITIVES Has evidence to support it Looks at structure AND process Enables us to make predictions

EVALUATING THE MULTI-STORE MEMORY

NEGATIVES Oversimplified Unitary stores Proposal of one short term store is wrong

(see next model) Proposal of one long term store is wrong

EVALUATING THE MULTI-STORE MEMORY Cohen & Squire (1980) distinguished between: declarative memories (memories for ‘knowing that’) and procedural memories (memories for ‘knowing how’) – people

with different conditions can lose one or the other, e.g. HM his STM was damaged but he could still learn skills (learned to play tennis)

Clive Wearing – musical ability still intact Sub-divisions of declarative = semantic

episodic (Tulving 1972) Evidence for this in brain scans using radioactive gold to

measure blood flow Model finds it difficult to explain flashbulb memories (these

can be autobiographical or historical) Examples are:

EVALUATING THE MULTI-STORE MEMORY

Rehearsal – now accepted that is not to only way into LTM

Levels of processing model (LOP) – depth of processing is more important

3 levels i) visual ii) phonetic iii) semantic Integrated STM and LTM not separate STM relies on LTM’s to chunk for instance e.g. AQABBCITVIBM Supporting evidence comes from artificial, un-

ecologically valid laboratory experiments

The Working Memory

See work sheet

Evaluating the Working Memory Model

POSITIVES Can explain partial memory difficulties e.g. case sudy of someone with normal LTM

but phonological loop difficulties Has plenty of research evidence, e.g. dual

task experiments Emphasizes the active nature of short term

memories

Evaluating the Working Memory Model

Ties in with brain mapping technology

Brain imaging studies have shown the separate areas at work, e.g. phonological store in Wernicke’s area and the articulatory rehearsal process in Broca’s area

Evaluating the Working Memory Model

NEGATIVES Little is known about the CE (vague concept) – its

probably also subdivided Using case studies of brain damaged people is

problematic Lab studies also have their drawbacks ????????

ACTIVITY

“Alice is ……

Levels of processing (LOP)

An alternative to the multistore model by Craik and Lockhart (1972) Emphasises memory process rather than

structure Based on the idea that the strength of a memory

trace is determined by how the original info was processed

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Levels of processing

Different levels of processing: Structural – appearance Phonological – auditory/sound Semantic – meaning

Structural is the shallowest, semantic is the deepest

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Levels of processing

Structural

Weak memory trace Strong memory trace

Phonological Semantic

Shallow processing Deep processing

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Levels of processing

Incoming stimuli pass through a series of analysing mechanisms

Memory traces are a product of how stimuli are analysed

Strength of trace depends on: Attention paid to stimulus Depth of processing carried out Connections with existing knowledge

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Levels of processing

The basic prediction of the LOP approach is that the amount of info P’s will recall/recognise will depend on how deeply the experimental stimuli were processed

Complete experiment into LOP

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Supporting evidence

Elias & Perfetti (1973) P’s had greater recognition of words they had

thought of similes for (semantic) than word they had thought of rhymes for (phono)

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Supporting evidence

Craik & Tulving (1975) Tested P’s in 3 ways:1. Is the word written in

capitals? BIRD (y/n)2. Does the word rhyme

with ‘love’? Dove (y/n)3. Complete the sentence

… ‘the man ate the … telephone/apple.’

Highest recognition of semantically processes stimuli, followed by phono, followed by structural

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structural

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semantic

Levels of processing - positives

Influential model that focused researchers on processes that they had tended to neglect

The idea that the nature of a memory trace depends on encoding processes is well supported by empirical evidence

Theory can be applied to everyday life, e.g. exam revision You will recall more if you use…

Depth – make sure you understand & make connections between the topics & ideas

Spread – use several different techniques on the material Elaboration – mental effort is required to store material

effectively Distinctiveness – make the material your own

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Levels of processing - negatives

Many different variables involved in determining how a stimulus is processed: Depth spread Elaboration Distinctiveness

Very difficult to isolate these variables experimentally

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Levels of processing - negatives

Semantic processing was not always best; it depended on how recall was measured and how relevant the task was (Morris et al (1977):

Recognition – semantic best Rhyming recognition – phonological best It is difficult to measure ‘depth’ P’s may not process the info the way you

want them to The theory ‘describes’ rather than ‘explains’

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Explanations of Forgetting

ACTIVITY – group work/presentations

Trace decay Displacement Lack of consolidation Interference Retrieval failure Motivated forgetting (repression)