Describe and evaluate the working memory model of memory (16 marks)

Baddeley and Hitch (1979) introduced their working memory model to challenge the multi store model of memory proposed by Atkinson and Shiffrin.

The working memory model is a cognitive model of short term memory comprised of three main components; the central executive, the visuo-spatial sketchpad and the phonological loop. Information is received via the senses and the sensory memory store either sends this on to working memory for processing or the information decays.

The central executive acts as a main controller, allocating information to the various components depending on what class of information it is.

The visuo-spatial sketchpad handles information relating to visual or spatial form. This store is particularly important in navigation.

The phonological loop processes written or spoken information. This is made up of two sub categories; the phonological store and the articulatory process.

Once information is processed, the central executive relays the information to the long term memory store where it can be retrieved when necessary. They suggest the components of working memory all have limited capacity.

Research that supports this model comes from Baddeley and Hitch (1976). They conducted an experiment where participants were asked to perform two tasks at the same time (dual task paradigm) - a digit span task which required them to repeat a list of numbers, and a verbal reasoning task which required them to answer true or false to various questions (e.g., B is followed by A?).

They found that as the number of digits increased in the digit span tasks, participants took longer to answer the reasoning questions. And, they didn't make any more errors in the verbal reasoning tasks as the number of digits increased. They concluded that these results suggested the verbal reasoning task uses the central executive, and the digit span task uses the phonological loop. Thus, supporting the concept of functionally specialised components that operate independently.

Further research supporting the working memory model comes from the KF Case Study. KF suffered brain damage from a motorcycle accident that damaged his short-term memory. KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected. This shows that there are separate STM components for visual information and verbal information.

A criticism of this model comes from Lieberman (1980), who suggested that the visuospatial sketchpad (VSS) implies that all spatial information was first visual. However, Lieberman points out that blind people have excellent spatial awareness, although they have never had any visual information. Lieberman argues that the VSS should be separated into two different components: one for visual information and one for spatial.