The Working Memory Model

How does the WMM differ from the MSM?

• MSM was limited as it only explained stores as single units

• Research shows there is multiple parts to the STM and LTM

Why did Baddeley and Hitch (1974) create the WMM?

It explains the different temporary stores of the STM

What are the four parts of the WMM?

• Central executive

• Phonological loop

• Visio-spatial sketchpad

• Episodic buffer

What is the function of the central executive?

‘Supervisor’ that monitors incoming data - focuses and divides our attention and allocates subsystems to tasks

Does the central executive have coding?

No

What is the central executive’s capacity?

Very limited as it doesn’t store information

What is the phonological loop?

Deals with auditory information and preserves the order in which information arrives

What two parts is the phonological loop split into?

• Phonological store: stores the words you hear

• Articulatory process: allows maintenance rehearsal, to keep items in working memory whilst they are needed

How is the phonological loop coded?

Acoustically

What is the capacity of the phonological loop?

Two seconds’ worth of words

What is the visio-spatial sketchpad?

Stores visual and spatial information

What are the two parts of the visuo-spatial sketchpad?

• Visual cache: stores visual data

• Inner scribe: records arrangements of objects in the visual field

Does the visuo-spatial sketchpad have coding?

No

What is the visuo-spatial sketchpad’s capacity?

3-4 objects (Baddeley 2003)

What is the episodic buffer?

Integrates visual, spatial and verbal information processed by other stores and recording events → storage for the CE

Does the episodic buffer have coding?

No

What is the episodic buffer’s capacity?

4 chunks (Baddeley 2012)

What are the strengths of the WMM?

• Clinical evidence

• Research support

What are the limitations of the WMM?

• Evidence from clinical studies may not be reliable

• Challenging evidence

• Lack of clarity over the nature of the CE

• Low external validity

• Other explanations

What clinical evidence is there to support the WMM?

• Shallice & Warrington (1970)’s case study of KF supports separate stores of STM

• After a brain injury sustained from a motorcycle accident, KF had a poor STM ability for auditory information, but could process visual information normally → he could recall digits and letters when he read them, but less when they were read to him. KF’s phonological loop was damaged but his VSS was intact

What research support is there for the WMM?

• Baddeley et al. (1970)’s participants carried out a dual-task, verbal and visual.

• When completing the dual-task, performance was similar to when performing tasks individually.

• When both tasks were visual/verbal, performance on both declined substantially → both tasks compete for the same subsystem, whereas a visual and verbal task require different parts of the STM.

• Shows there must be a separate subsystem for processing visual (VSS) and verbal (PL) output.

How is the clinical evidence limited?

KF may have had other cognitive impairments other than damage to his PL → this could have affected his performance on memory tasks.

What challenging evidence is there against the WMM?

• Case study of EVR: he suffered a brain tumour, which was removed from the frontal lobes of his brain.

• His IQ was above average, memory was good, and scored high on reasoning tests

• However, he found it impossible to make decisions → think through things logically

• Demonstrates that the CE cannot be one part, as both logical decision and reasoning tests would have used the CE

Why is there lack of clarity over the nature of the CE?

• Some psychologists suggest the CE contains subcomponents

• The CE’s function is too vague: ‘attention’

Why does the WMM have low external validity?

• Dual-task study used artificial tasks that are not representative of everyday life

• Carried out in highly-controlled lab conditions

• High internal validity but low external