Multi-store model

Multi-store model

1. Sensory register: information comes from the senses, capacity is unlimited, duration of up to 2 seconds, modality specific

2. STM: If there is attention then info moves to STM, capacity 7+/-2, duration 30 seconds, encodes acoustically

3. LTM: if info is rehearsed it moves to LTM, capacity and duration is potentially limitless, encodes semantically

4. Serial position effect: Primacy and recency effect - First words transfer to LTM, last words are still in STM but have displaced the words in the middle

5. Brain damaged patients HM – amnesia following brain surgery for epilepsy Severely impaired LTM but intact STM However Clive was unable to recall past events but could play the piano and conduct an orchestra – evidence for different types of LTM not accounted for in multi-store model KC – motorcycle accident – could recall facts but not personal events

6. Includes detail of structure and process Has Stimulated a lot of research leading to better understanding of memory Applications – helps rehabilitation with brain damaged patients

   • Working memory model
     • Central executive – Limited capacity, General processing, Homunculus, Modality free, Attentional Controller, focus, divide and switch attention
     • Phonological loop – Slave system, Temporary storage of verbal info, Articulatory rehearsal system – explains the word length effect (longer words take up the capacity) Phonological store – explains the phonological similarity effect (can remember more dissimilar sounding words)
       • Tulving LTM
         • Episodic - experiences, Semantic – facts
         • Semantic – mental encyclopedia, stored words, facts, meanings, rules and concepts Eg june follows may in the calendar, inputted in a more fragmented way, info can be learned at different times and places and integrated later because of its meaning, not dependent on context, recall based on inferences, generalisation, rational, logical thought, recalled unchanged from its original form
         • Episodic – mental diary, stored experiences and events, linked to times and context, memories linked to the times that they occurred eg first day at school, input is continuous events occur in chronological order, dependent on context in which it was learned, recall aided by context cues, susceptible to transformation
           • Reconstructive memory
             • ‘War of the Ghosts’ Unfamiliar to ppts Lacked rational story order Dramatic nature Supernatural conclusion. Read the story twice. Repeated reproduction method – 20 ppts recall the story at different intervals minutes, weeks, months and years (longest 6.5 years) Got shorter by omission Phrases reflected modern concepts (hunting seals changed to fishing) Story became more coherent
             • Schema- parcels of stored knowledge Each has fixed information and variable information Fixed – eg going to a restaurant, being waited on, eating, paying Variable - eg the menu, how much it cost. We do not remember all that we percieve, we fill in gaps in memory using expectations and beliefs Memory is an active reconstruction of events Explains the ‘effort after meaning’ effect
               • Developmental psychology
                 • Dyselxia - reading disorder – difficulty learning to recognise and decode printed words but normal comprehension Affects between 3 and 5% of children More prevalent in boys than girls Difficulty associating words with sounds (phonology) leads to spelling and reading problems Poor verbal short term memory (evidence from word length effect and phonological similarity effect)
                 • McDougal et al 1994 90 children – three different reading groups Poor, moderate and good readers Poor readers had poor memory for words and slow reading rate Good readers articulate words quickly, more words represented in STM memory phonologically Poor readers sound out words slowly taking up more space in STM
                 • Difficult to establish cause and effect with memory deficits as dyslexics show a range of visual and auditory impairments Also dyslexia is comorbid with other disorders like ADHD so interaction is unclear and makes it difficult to isolate phonological issues as a reason for impairment
                 • Alzheimer's Disease - Progressive, degenerative, neurological disorder associated with aging Affects 1 in 20 people Most common form of dementia Typically over 65 years old, central executive affected making tasks difficult to coordinate Inability to recall autobiographical information from episodic memory Linked to loss of brain matter, particularly hippocampus and temporal cortex Loss of executive function = lack of general coordination, difficulty with attention. Difficulty with dual tasks
             • He used 8 different stories and found similar results and with repeated reproduction of pictures Schema effects recall part of memory but can have an effect at learning too as we draw on schemas to comprehend a situation Has led to the view that memory is inaccurate and unreliable, other research suggests that eyewitness testimony and recall can be very accurate using a different research method in a real life context
         • KC – motorbike accident – impaired episodic, intact semantic – evidence for separate stores KC and Clive wearing could recall how to perform tasks (piano playing), this points to a third type of long term memory, Procedural memory
     • Visuo-spatial sketchpad (VSSP) Slave system, Temporary store of visual and spatial info, Deals with direct visual and spatial info or visual and spatial info from LTM Capacity is limited
     • KF – motorbike accident – impaired short term memory – digit span of 1 (phonological) but visual memory was intact HM – impaired spatial memory, intact STM for verbal info
     • Dual task experiments – a visual and phonological task could be completed easily, Two tasks using the same slave system are easier to perform – evidence for separate, Visual tasks more disrupted by visual interference and spatial tasks more disrupted by spatial interference, Alzheimer’s disease Less research on central executive but worse in Alzheimer’s patients – performed worse on dual task experiments showing loss of central executive function