The working memory model: central executive, phonological loop, visuo-spatial sketchpad and episodic buffer. Features of the model: coding and capacity.

The Working Memory Model (WMM) – Baddeley and Hitch (1974)

Description, AO1 The Working Memory Model

WMM Diagram

Baddeley & Hitch’s (1974) Working Memory Model (WMM) arose out of criticisms aimed at the Multi-Store Model (MSM), particularly the idea that STM was a unitary store – to test this Baddeley and Hitch devised the dual-task technique.

(1) Central Executive:

  • Coordinates the activity of the STM
  • Delegates information to the slave systems
  • Limited capacity
  • Modality free
  • Retrieves information from the LTM

Research: D’Esposito et al found using MRI scans the prefrontal cortex was activated when verbal and spatial tasks were preformed simultaneously but not when performed separately, suggesting the brain area indicates the working of the CE.

Evaluation, A03 – Little is known about the CE, therefore it is very difficult to know exactly what its role is in memory.

 

(2) Phonological loop:

  • Deals with auditory information (inc written words)
  • Limited capacity
  • Made up of primary acoustic store & articulatory process
  • Phonological Store (inner ear) stores words recently heard
  • Articulatory Process (inner voice) keeps information in the Phonological Store through repetition

(3) Visuo-spatial sketchpad:

  • Deals with visual and spatial information
  • Helps the individual navigate and interact with their physical environment.
  • Visual cache (form & colour)
  • Inner scribe (spatial, transfer into in the VC to the CE)
  • Inner eye
  • Limited capacity

 

(4) Episodic buffer:

  • Component added to the model in 2000
  • Integrates information from Central Execuative, Phonological Loop and Visuo-Spatial Sketchpad
  • Retrieves information from LTM

 

Evaluation, AO3 of the Working Memory Model (WMM):

Strengths:

(1) Point: There is physiological evidence to support the WMM: Evidence: For example, PET (positron emission tomography) scans have shown that different areas of the brain are used whilst undertaking visual and verbal tasks which may correspond to the visuo-spatial sketchpad and phonological loop of WMM. Evaluation: This is positive as it provides objective and scientific support for the view that visual and verbal material is dealt with by separate structures that may even be physically separate, this increases the credibility of the WMM as an accurate representation of memory.

 

(2) Point: Support for the working memory model comes from the case study of KF. Evidence: For example, KF suffered a motorcycle accident and was left with considerable damage to his memory. His short-term forgetting of auditory information was greater than for visual information, suggesting that his memory damage was restricted to the phonological loop. Evaluation: This is a strength because it demonstrates that it’s possible to damage just part of the short-term memory, which can be accounted for by the WMM, as if all short-term memories were stored in the same place KF’s entire STM would be damaged.

 

Weaknesses:

(1) Point: A weakness of the WMM is that it fails to account for musical memory. Evidence: Evidence for this comes from Berz (1995) who demonstrated that participants could listen to instrumental music (music without words) without impairing performance on other acoustic tasks. Evaluation: This is problematic because it appears that 2 auditory tasks can be completed at the same time which suggests memory is more complicated than the WMM suggests. According to the WMM we would expect participants to not be able to complete both tasks as they would use the same store.

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