the working memory model

• Working memory model (WMM)

  Created by Baddeley and Hitch (1974) to replace the STM store of the MSM due to criticisms of the STM. An explanation that sees STM as an active store holding several pieces of information simultaneously.
• Central executive


  The part of working memory that is responsible for monitoring and directing attention. It receives sense information and filters this before passing it onto the subsystems. Limited in capacity (4 items), working on one type of information at a time.
• Phonological loop


  Processes auditory coded information.

  Phonological store: the inner ear, holding words recently heard.

  Articulatory process: the inner voice, holds information via sub-vocal repetition.

  Has a limited capacity of what can be said in 2 seconds.
• What is the phonological loop divided into?

  Phonological store and articulatory process
• Visuo-spatial sketchpad


  Processes visual and spatially coded information, thought of as the 'inner eye'.

  Visual cache: A passive store of form and colour (things you see)

  Inner scribe: Active store holding the relationships between objects in 3D space.

  Capacity - holds 3 or 4 objects (Baddeley)
• What is the visuo-spatial sketchpad divided into?

  Visual cache and inner scribe
• Episodic buffer


  Added to WMM in 2000, as the model needed a general store incorporate information from the central executive, phonological loop, visuo-spatial sketchpad and LTM.
• + Supporting evidence from case studies


  E - Shallice and Warrington - K.F struggled to process verbal information but his visual memory was unaffected. His phonological loop was damaged.

  E- This supports the existence of a separate visual and acoustic stores aka the PL and VSS.

  L - However, evidence from brain damaged patients may not be reliable because they are unique cases of people who have suffered traumatic experiences. We cannot generalise results.
• + Supporting evidence from dual task studies


  E - Baddeley et al: Ps had more difficulty doing two visual tasks (Tracking a light and describing the letter F) than doing a visual and verbal task at the same time. Performance is better when not using the same processing.

  E - Suggests that the visuo-spatial sketchpad and phonological loop exist as separate systems and the capacity of the VSS can be overwhelmed with visual information.

  L - Therefore, this research supports the WMM and increases the validity of the model.
• - Lack of clarity over the central executive


  E - Baddeley's definition of the central executive is unsatisfactory and doesn't really explain anything. The central executive needs to be more clearly explained than just being simply 'attention'.

  E - It is the most important part of the model, but is the one we know the least about.

  L - Therefore, the concept of the WMM still needs development in order to fully explain the process of memory.
• WMM

  
• / Lacks research support that has ecological validity


  E - Most research support has artificial and highly controlled stimuli, lab conditions and tasks. E.g. in the dual-task study, the order of letters had to be identified correctly.

  E - These tasks don't occur commonly in life so the WMM may not explain how memory works in day to day life and tasks.

  L - Therefore, the model lacks ecological validity and might not actually apply to the general population.