Working Memory Model

Working Memory Model

1. Baddeley and Hitch

   • Questioned existence of a single store (in MSM) for STM
     • STM more complex than just temporary store for transferring info into LTM
     • Saw STM as an 'active' store
       • Holding several pieces of info whilst being worked on
       • Active, not just a store
   • Proposed a multi-component model comprising of 3 components
     • Central Executive
     • Phonological Loop
     • Visuo-spatial sketchpad
   • Evidence: Baddeley- dual task technique
     • If two tasks require different components performance reasonably ok
     • If two tasks require same component performance suffers
     • Methodology
       • Task 1: 2 statements given to p's
         • Required to state whether the order is true or false as quickly as possible
       • Task 2: Whilst given one of 3 tasks
         • P's required to repeat 'the' over and over again (occupies articulatory loop)
         • P's had to say random digits out loud (occupying CE + PL)
         • P's not required to complete second task
     • Findings
       • When task 1 combined with repeating 'the' or not doing second task; performance not affected
       • When task 1 combined with saying random digits; speed dropped significantly
       • Conclusion
         • Doing two tasks that use same component of memory causes difficultly
         • Supporting the idea of a separate stores for different types of info

2. Central Executive

   • Involved in higher mental processes
     • Decision making
     • Problem-solving
   • co-ordinates performances on two separate tasks
   • Attends to one input whilst inhibiting others
   • Limited capacity
   • Criticisms
     • Vague
     • Don't know how it works/what it does
     • Capacity unknown
   • Can be used to explain any results
   • Located in pre-frontal cortex
     • Evidence: D'Esposito et al
       • fMRI scans
         • Pre-frontal cortex activated when verbal and spatial tasks performed simultaneously
         • not activated when verbal and spatial tasks performed seperately
         • Suggesting CE switches input between slave systems to perform both tasks
           • Co-ordinates performances on two separate tasks
   • Switches input between two 'slave' systems

3. Phonological loop

   • Deals with auditory info
   • Limited Capacity
     • Determined by the amount of information spoken out loud in about 2 secs
   • Deals with order of info
   • Primarily acoustic store
     • Acoustic confusion with similar-sounding words
   • Divided into two sub-parts
     • Phonological store
       • Inner-ear
       • Stores words heard
         • In acoustic code
       • Passive
     • Articulatory loop
       • Inner-voice
       • Allows sub-vocal repitition whilst preparing to speak
   • Evidence: Word-length effect
     • Gave visual presentations of word lists for brief time
       • Then asked to write them down in serial order
     • One list: familiar monosyllabic words
       • Second list: Polysyllabic words
     • Conclusion
       • Capacity of loop determined by length of time taken to say the words rather than number of items in list
         • Estimated time: 1.5 seconds
       • Supports idea of PL holding auditory information
     • Findings
       • Average correct recall over several trials- superiority for short words
     • Laboratory experiment
   • Slave system

4. Visuo-spatial sketchpad

   • Inner-eye
   • Non-phonological info
   • Temporary store visual and spatial items and relationship between them
     • Essentially a store for what items are and where they are located
     • Helps individuals interact and navigate with their physical environment
       • With information rehearsed and encoded through use of mental pictures
   • Consists of two sub-parts
     • Visual cache
       • Passive part
       • Stores visual material about form and colour
     • Inner scribe
       • Active part
       • Stores info about spatial relationships
   • Helps rehearse visual or spatial info
   • Uses visual code
     • Visually organises info
   • Evidence; Klauer and Zhao
     • More interference between two visual tasks than between visual and spatial tasks
       • Implying existence of a separate visual cache and inner scribe
   • Slave system

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