memory

memory

1. multi-store model of memory

   • ao1
     • a structural model proposed by atkinson and shiffrin, they proposed that memory was composed of three stores, sensory register, short term memory and long term memory. information passes from store to store in a linear way and both STM and LTM are unitary stores.
     • sensory information is the information that you get from your senses, your eyes and ears specifically, when attention is payed to something in the environment, it is then converted into short term memory
       • information from the short term memory is only converted into long term memory if it is rehearsed (i.e. repeated)
         • maintenance rehearsal is repetition that keeps information in the short term memory but will eventually create a long term memory. if maintenance rehearsal does not occur then information will be forgotten, lost from the short term memory through displacement or decay.
     • encoding, capacity and duration.
       • sensory register
         • encoding: sense specific (e.g. different stores for each sense) capacity: all sense capacity (very large capacity) duration 1/4 to 1/2 a second
       • STM
         • encoding: mainly acoustic (hearing) capacity: 7 +/- 2 items (5-9 items) duration: 0-18 seconds
       • LTM
         • encoding: mainly semantic (but can be acoustic or visual) capacity: unlimited duration: unlimited
   • ao3
     • positive
       • this model gives a good baseline understanding of STM and therefore allows researchers to expand on this model and make it more valid
       • this model has support in the study of amnesiacs, e.g. H.M. who has struggles with his LTM after brain surgery, he remembers little of personal (e.g. death of parents) or public (e.g. watergate, vietnam war) events but his STM remains intact
     • negative
       • however this theory has been criticised as being too simple, and recent developments lead us to believe that STM and LTM are actually far more intertwined than we perviously thought, for example, the working memory model proposed by baddeley and hitch (1974) proposes that STM is not a unitary store and instead comprises of multiple components
       • this model places large importance on rehearsal in the transfer of information from the STM to the LTM, however this is not essential, as we are able to recall information that we did not rehearse (e.g. swimming) whilst we are not able to recall information that we did rehearse (e.g. revision)
   • research
     • glanzer and cunitz
       • when participants are presented with a list of words they tend to remember the first and last words more accurately than they remember the words in the middle, i.e. the serial position effect. this supports the existence of a separate STM and LTM as they observed a primacy and regency effect.
         • primacy effect
           • words at the front of the list were put into long term memory as the person had more time to rehearse the word
         • regency effect
           • words at the end of the list were put into STM
     • KF (shallice and warrington (1970)) was in a motorcycle crash that resulted in brain damage, his LTM appeared to be unaffected however he was only able to recall the last bit of information from his STM

2. working memory model

   • ao1
     • key features include the central executive, episodic buffer, phonological loop and the visuospatial sketchpad
       • central exectuive
         • has a supervisory function, has a small capacity and deals with only one piece of information at a time, it determines which information is attended to, and by which slave systems, it can process information in all sensory forms and collect responses from slave systems
       • slave systems
         • phonological loop
           • temporary storage system for dealing with auditory information in a speech based form, it has two parts.
           • plays a big role in the development of reading
           • phonological store
             • (1) the phonological store (inner ear) which stores words you hear
           • articulatory process
             • (2) the articulatory process (inner voice), which allows maintenance rehearsal.
         • visuospatial sketchpad
           • the VSS is a temporary storage unit for visual and spatial information. it has two parts.
           • visual cache
             • stores visual data about form and colour
           • inner scribe
             • records the arrangement of objects in the visual field and rehearses and transfers information in the visual cache to the central executive
         • episodic buffer
           • acts as a 'baskup' for (temporary) storage and communicates between LTM and slave systems in the working memory model
           • one of it's important functions is to recall information from LTM and integrate it into the STM when working memory requires it
   • ao3
     • positive
       • working memory model is supported by dual task studies - it is easier to do two tasks at the same time if they use different slave systems than if they use the same processing system (e.g. verbal and visual)
       • KF's study also supports the working memory model as KF suffered a motorcycle accident that damaged his STM, his impairment was mainly for verbal information, his ability to retain visual information remained largely unaffected
         • however, evidence used from brain damaged patients may not be generalisable to the wider population as it concerns very unique and traumatic cases and circumstances
     • negative
       • little is known about how the central executive works, it is an important part of the model yet it's exact role is unclear
       • this model doesn't explain the link between working memory and LTM
   • research
     • baddeley and hitch (1974)
       • results
         • as the number of digits in the digit span section increased, the patients took increasing ly longer to answer the true or false questions, but not much longer - only a matter of fractions of seconds, and the number of errors they made didn't increase in the reasoning questions as the number of digits increased
       • conclusion
         • the verbal reasoning task made use of the central executive and the digit span task made use of the phonological loop
       • procedure
         • participants were asked to perform two tasks at the same time (dual task technique), a digit span task which required them to repeat a list of numbers and a verbal reasoning task which required them to answer various true or false questions

3. improving the accuracy of eyewitness testimony

   • cognitive interview
     • a police technique which encourages the witness to recreate the original context in order to retrieve the maximum amount of stored information
     • techniques
       • context reinstatement
         • trying to mentally recreate an image of the situation, including details of the environment, such as weather conditions, smells, sounds, and the individuals emotional state, such as their feelings at the time of the incident
         • this makes memories accessible which provides emotional and contextual cues
       • recall from a changed perspective
         • trying to mentally recreate the situation from different points of view (e.g. what another witness at the time would have seen)
         • this is used to disrupt the effect that schemas have on recall
       • recall in reverse order
         • he witness is asked to recall the scene in a different chronological order (e.g. end to beginning)
         • our recollections are based in our schema, if your recall a situation from end to beginning this prevents your pre-existing schema
       • report everything
         • the interviewer encourages the witness to recall all the details or the events, no matter how unimportant they may seem
         • memories are interconnected, so the recollection of little seemingly unimportant details may then cue a lot of other important memories
     • enhanced cognitive interview
       • add ons include; encouraging the witness to breathe, relax and talk slowly. offering comments to help clarify witness statements. adapt questions to suit the understanding of individual witnesses.
     • ao3
       • negative
         • time consuming; it is very time consuming to conduct a cognitive interview, and to train police officers in how to properly conduct one, this means that it is unlikely that the 'proper' version of the cognitive interview is used
         • some elements of the cognitive interview may be more useful than others, for example, studies show that the cognitive interview is more effective when both 'recall everything' and 'context reinstatement' than any of the other elements individually
         • training police personnel is both time consuming and very expensive
       • positive
         • geiselman (1985)
           • participants were shown footage of a violent crime and after 48 hours they were interviewed by the police using either the cognitive interview, hypnosis, or a standard interview, both the number of facts accurately recalled and the number of errors made were recorded and compared
             • the average number of correctly recalled facts for the cognitive interview was 41.2, for hypnosis it was 38.0 and for the standard interview it was 29.4

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