How to Answer a Contrast ERQ (DP IB Psychology)

Contrast two models of memory [22 marks]

Commentary

A model is a visual representation designed to explain a theory. Atkinson and Shiffrin’s (1968) multi-store memory model (MSM) is a model explaining their theory of memory. It explains how information flows through three stores, each having different capacities and durations:  sensory memory, short-term memory and long-term memory.  Baddeley & Hitch (1974) developed an alternative model of short-term memory that they called the working memory model (WMM). This essay will focus on the differences between the models.

There are several ways in which these two models differ. The first is that the MSM is a complete model of memory, while the WMM is a model of short-term memory only, though it explains how the backup store of the episodic buffer communicates with both long-term and short-term memory. The MSM presents memory as a linear process whereas the WMM conceptualises the dynamism of memory.

A second point of contrast is that the MSM is a static model that suggests separate stores for sensory, short-term and long-term memory.  It explains how information flows sequentially through these three stores, each having different capacities and durations. Information is encoded through paying attention to the structure and sound, and by repetition, in order to pass from one store to another. The WMM, however, presents short-term memory as a dynamic and complex information processor rather than a static store.  

While the WMM can accommodate Atkinson and Shiffrin’s theory of separate stores for different types of memory as seen in the MSM, it is a dynamic, rather than a static, model. Nor is the WMM linear – it does not assume that information has to pass through a static short-term memory to enter long-term memory. Instead, the central executive and episodic buffer coordinate back and forth between the short-term and long-term memories. This means that Shallice and Warrington’s (1969) study showing that a young man with impaired short-term memory after an accident still had intact long-term memory can be explained by the working memory model, with the articulatory control system affected, but the central executive remaining intact.  

The WMM, in contrast to the MSM, can explain parallel processing of information, involving attending to visual and auditory data at the same time, by using both the phonological store and the visuo-spatial sketchpad. The MSM can only show the progression of memory from one store to another, with the only arguably dynamic element being the rehearsal loop. The WMM does not accommodate a rehearsal procedure so it lacks an explanation as to how short-term memories enter long-term memory storage.

Baddeley (2000) updated the working memory model after it failed to explain the results of various experiments, adding the episodic buffer. The episodic buffer acts as a 'backup' store that communicates with both long-term memory and the components of working memory (although, even with this in place, the role of long-term memory in the WMM is still rather vague). This addition means that the WMM is far more complex and sophisticated than the MSM.

Dual-task studies give empirical support for the existence of a separate phonological loop and visuo-spatial sketchpad: Robbins et al. (1996) found that chess used the visuo-spatial sketchpad and suffered no interference from the rapid repetition of the word see-saw (using the phonological loop), but random number generation or tapping numbers on a keypad reduced the ability to make chess moves. So, instead of separate stores, the working memory model is a model of parallel processes.

The MSM gains support from studies of serial position effect (e.g. Glanzer & Cunitz, 1966) which are rather more simplistic and less taxing for participants, underlining the lack of sophistication in the model compared to the WMM.

In conclusion, the MSM is a complete theory of memory, from sensory to long-term memory, while the WMM is a conceptualisation of short-term memory only. The MSM views short-term memory as a unitary store wherein material is retained through repetition and the focus is on capacity, encoding and duration, with material processed mainly acoustically. The WMM depicts short-term memory as a processing area, divided into three interacting components: the central executive, the phonological loop and the visuo-spatial sketchpad. The episodic buffer that was added later by Baddeley acts to mediate between short-term memory and long-term memory. The WMM can also be used to explain processes such as thinking and problem-solving.

A key point of contrast between the two models is, crucially, that the WMM is the model of short-term memory that is most widely used today.

Introduction and focus on the question: the two models are introduced straight away. The ‘Contrast’ command term is directly addressed.

Knowledge and understanding of both models are shown. Emphasis on the major differences between them is discussed.

The ‘Contrast’ command term is explored further.

The contrast in the presentation of each model is explored, and linked with a specific example. 

This point of contrast focuses on the functioning of each model.

The degree of complexity of each model is contrasted.

The methodology per model is contrasted with specific examples. 

The conclusion sums up what the essay has covered and reaches a final judgment.

Word count: 750

[22 marks]