Working Memory Model

• Working memory model

  • Baddeley and Hitch (1974)

  
• Central executive

  • capacity - limited processing
  • coding - modality free (not limited to sight or sound as it needs to use all manner of information)
  • acts as a filter to determine which information is received by the sense organs
  • processes information in all sensory forms
  • limited processing capacity
  • does not store information
  • can only effectively cope with one strand of information at a time
  • allows us to switch between inputs of information and maintains a balance between tasks when attention must be divided between them
• Visuo-spatial sketchpad

  • capacity - 3 to 4 objects
  • coding - visual
  • the "inner eye"
  • the temporary store for visual and spatial items
  • helps individuals navigate around and interact with their physical environment, with information being coded and rehearsed using mental pictures
  • the visual cache stores visual data about form and colour
  • the inner scribe handles spatial relationships and rehearses/transfers information to the central executive
• Phonological Loop

  • capacity - 2 seconds worth of information
  • coding - acoustic
  • deals with acoustic information and its order
  • similar to the rehearsal system for the MSM
  • it has a limited capacity and is divided into 2 main subparts: the acoustic store (inner ear) stores words that have been recently heard, and the articulatory control (inner voice) keeps sounds or words in the working memory through repetition
• Episodic buffer

  • capacity - 4 chunks
  • coding - modality free (in any form)
  • temporarily stores information combined together from the CE, phonological loop and LTM.
  • has a limited capacity
  • can be seen as the storage component of the CE
• A03 - limitation


  • A limitation is that the nature of the central executive is unclear
  • Baddeley states that the central executive is the most important but least understood part of the working memory model
  • Some psychologists believe that it may involve several subcomponents rather than just being mainly involved in attention
  • Limited research to support its role and challenges the integrity of the WMM
• A03- supporting evidence


  • There is supporting evidence for the CE being located in the prefrontal cortex area of the brain
  • D'Esposito et al used fMRI scans and found that the prefrontal cortex was active when spatial and verbal tasks were done simultaneously but not when performed separately.
• A03 - supporting evidence

  • Baddeley
  • supports the idea that the visuo-spatial sketchpad has a limited capacity of 3/4 items
  • Ps were asked to imagine objects mentally
  • When the number of objects exceeded 5, this task became very difficult
• A03- evidence


  • Baddeley
  • supports the idea that there is a limited capacity of the phonological loop
  • Ps given lists of short words and long words to recall
  • recall higher on short words than long words
  • the number it can hold relates to how much can be stored in two seconds
• A03- dual task performance

  • Gathercole and Baddeley
  • Ps track a moving point of light
  • at the same time, Ps describe the angle of a hollow letter F
  • Ps had difficulty as both tasks involved the VSS
  • indicates the VSS is a separate slave system
• A03- case study evidence

  • Shallice and Warrington
  • reported that patient KF had a better recall of digits and letters when he read them (visual) to when they were read to him (acoustic) which supports the existence of separate visual and acoustic memory stores
• A03- value


  Advantages over the MSM

  • working memory involves both active processing and storage of information
  • is involved in all complex tasks and can explain how we do different tasks at the same time
  • explains partial short term memory deficits which are sometimes caused by brain damage
  • incorporates verbal rehearsal as an optional process which is more realistic than the MSM which has it as very significant