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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
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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 memory Short term and long term memories are permanent, structural components
SUPPORTING EVIDENCE (mini experiment) • PRIMACY/ RECENCY EFFECT (Murdock 1962) • 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) www.psychlotron.org.uk • 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
Levels of processing www.psychlotron.org.uk • Different levels of processing: • Structural – appearance • Phonological – auditory/sound • Semantic – meaning • Structural is the shallowest, semantic is the deepest
Shallow processing Deep processing Structural Phonological Semantic Weak memory trace Strong memory trace Levels of processing www.psychlotron.org.uk
Levels of processing www.psychlotron.org.uk • 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
Levels of processing www.psychlotron.org.uk • 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
Supporting evidence www.psychlotron.org.uk • 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)
Supporting evidence • Craik & Tulving (1975) • Tested P’s in 3 ways: • Is the word written in capitals? BIRD (y/n) • Does the word rhyme with ‘love’? Dove (y/n) • Complete the sentence … ‘the man ate the … telephone/apple.’ • Highest recognition of semantically processes stimuli, followed by phono, followed by structural
Levels of processing - positives www.psychlotron.org.uk • 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
Levels of processing - negatives www.psychlotron.org.uk • Many different variables involved in determining how a stimulus is processed: • Depth • spread • Elaboration • Distinctiveness • Very difficult to isolate these variables experimentally
Levels of processing - negatives www.psychlotron.org.uk • 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’
Explanations of Forgetting ACTIVITY – group work/presentations • Trace decay • Displacement • Lack of consolidation • Interference • Retrieval failure • Motivated forgetting (repression)