Working Memory

Working Memory

1. Alternative model of short-term memory. Keeps track of transient information + Co-ordinates mental operations involved in cognitive tasks

   • Baddeley and Hitch (1974)

2. (STM) provided by the Multi-Store Model is far too simple.

3. Central Executive

   • located within the frontal cortex
   • Controls the whole system
     • Supervisory attentional system (Norman and Shallice, 1986)
   • allocates information to the subsystems
   • deals with cognitive tasks
     • eg: problem solving or arithmetic
   • most versatile + important component of the working memory system.
     • Alzheimer’s patients have a loss of mental functioning asa result of reduced central executive functioning
     • Dysexecutive syndrome (DES) common pattern of dysfunction in executive functions, such as planning, abstract thinking, flexibility and behavioural control as a result of impaired central executive.

4. Visuo-Spatial Sketch Pad

   • Stores + processes visual/spatial information.
     • eg: used for navigation
     • Visual and spatial task performed at same time do not interfere with each other (Baddeley and Lieberman, 1980
   • also displays & manipulates visual & spatial information held in LTM

5. Phonological Loop

   • Phonological similarity effect: errors are more likely on the letters that sound similar. Conrad & Hull, 1964
   • Evidence: Some brain damaged patients have a damaged phonological store but intact intact articulatory control process  proving that they are separate components. Shallice and Butterworth, 1970
   • Processes spoken + written information
     • eg: used for remembering a telephone number.
   • Phonological Store
     • eg: inner ear
     • Holds information in speech-based form for 1-2 seconds
       • Word Length Effect more challenging to remember a list of long words compared to a list of short words as it takes longer to rehearse the long words. Baddeley et al 1975
     • Spoken words enter the store directly. Written words must first be converted into spoken code before they can enter the phonological store.
   • Articulatory control process
     • eg: inner voice
     • Used to rehearse & store verbal information from phonological store.
     • converts written material into an articulatory code & transfers it to the phonological store

6. every component of working memory has a limited capacity & is relatively independent

7. 2 tasks that use of the same component cannot be performed successfully together

8. Episodic Buffer

   • updated by Baddeley (2000)
   • acts as a 'backup' store which communicates with both LTM & the components of working memory

9. Strengths

   • explains a lot more than the multi-store model
   • supported by experimental evidence
     • KF Case Study shows that there are separate STM components for visual information (VSS) and verbal information (phonological loop) as KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected.
     • dual task studies (Baddeley and Hitch, 1976 when chess players were given additional tasks that used a compenment that was already processing information their performance at chess decreased Robbins et al., 1996
   • applies to real life tasks
     • reading (phonological loop) - problem solving (central executive) - navigation (visual and spatial processing)

10. Limitations

    • blind people have excellent spatial awareness although they have never had any visual information. VSS should be separated into 2 different components
      • Lieberman
    • little evidence for how the central executive works
    • not a comprehensive model of memory as it does not include SM or LTM