The working memory model

Who created the working memory model?

Baddeley and Hitch

What is the working memory model?

A representation of STM

Suggests that STM is a dynamic processor of different types of info using subunits co-ordinated by a central decision making system.

What are the four main components of the working memory model?

• Central executive

• Phonological loop

• Visuo-spatial sketchpad

• Episodic buffer

What is the central executive?

• Supervisory component

• Modality free (processes all different types of info from all senses)

• Limited capacity and does not store info

• Monitors incoming data, focuses and divides our limited attention and allocates subsystems to tasks

What is the phonological loop?

• Slave system

• Limited capacity

• Deals with auditory info

• Has two subdivisions

• The capacity is how much can be said in 2 seconds

• The phonological store is a temporary storage system for holding auditory info. It stores the words you hear and has limited capacity

• The articulatory process focuses on words maintained by vocal repetition and has limited capacity

What is the visuospatial sketchpad?

• Slave system

• Temporarily stores visual/spatial info when required

• Visual info is what things look like

• Spatial info is the physical relationship between things

• Capacity of 3 or 4 objects

It is composed of:

• Visual cache - Stores visual data

• Inner scribe - Records the arrangement of objects in the visual field (spatial)

What is the episodic buffer?

• 3rd slave system

• Added by Baddeley in 2000

• Temporary store for info which integrates the visual, spatial and verbal info processed by other stores and maintaining a sense of time sequencing

• Links working memory to LTM and wider cognitive processes such as perception

• Capacity of about 4 chunks.

What is a strength of the working memory model? (Shallice and Warrington)

Support from Shallice and Warrington’s case study of patient KF

After his brain injury, KF had poor STM ability for auditory info but could process visual info normally.

E.g. his immediate recall of letters and digits was better when he read them (visual) than when they were read to him (acoustic).

KF’s phonological loop was damaged but his visuo-spatial sketchpad was intact.

This finding strongly supports the existence of separate visual and acoustic memory stores.

What is a counterpoint for Shallice and Warrington for the working memory model? (Patient KF)

Patient KF’s injury was caused by a motorcycle accident.

This trauma may have affected his cognitive performance which could have affected his performance on memory tasks.

This challenges evidence that comes from clinical studies of people with brain injuries that may have affected many different systems.

What is another strength of the working memory model? (Baddeley et al)

Studies of dual-task performance support the separate existence of the visuo-spatial sketchpad.

When Baddeley et al’s participants carried out a visual and verbal task at the same time, their performance on each was similar to when they carried out the tasks separately.

But when both tasks were visual, performance on both declines substantially.

This is because both visual tasks compete for the same subsystem (VSS), whereas there is no competition when performing a verbal and visual task together.

This shows there must be a separate subsystem that processes visual input.

What is a limitation of the working memory model? (Baddeley)

Lack of clarity over the nature of the CE

Baddeley said ‘The central executive is the most important but the least understood component of working memory’

The CE needs to be more clearly specified than just being simply ‘attention’

E.g. some psychologists believe the CE is an unsatisfactory component and this challenges the integrity of the WMM.

What is another limitation of the working memory model? (Lacks validity)

Lacks validity

Studies that support the WMM use tasks that are unlike the tasks we perform in everyday life (e.g. identifying the correct order of letter such as A and B or recalling sequences)

They are also carried out in highly controlled lab conditions where presentation of stimuli is precisely timed.