outline and evaluate the working memory model (essay)

first paragraph (assumptions)

The working memory model is a model of STM which suggests it is involved in reasoning and information processing as well as storage. WMM has four components: The central executive, which has overall control and allocates tasks to slave systems. There are two slave systems, the phonological loop and the Visual spatial sketchpad. There is also the Episodic Buffer, which is responsible for integrating visual and acoustic information so that memory can be stored as one continuous episode. It also time stamps the memory.

second paragraph (roles of each function in the model)

The central executive's functions also include directing attention to particular tasks, switching between tasks, correcting errors and retrieving information from LTM. The phonological loop is the part of WM that deals with acoustic information. It contains a phonological store, which stores the words you hear, and an articulatory control system, which is an active rehearsal system. The visuo-spatial sketchpad (VSS) deals with visual and spatial information. It contains the visual cache, which is a store of visual information, and an inner scribe, which rehearses visual information. In the WMM there is a two-way communication with the LTM so that we can make new memories relate to old memories.

third paragraph (strength - influential)

Some strengths of the model are that it has been extremely influential and many psychologists use the term 'working memory' in preference to 'STM' as it explains STM both in terms of storage and active processes. It is a much more useful model than MSM, indeed working memory tests are used as recruitment tools in industry.

fourth paragraph (strength - explains findings from memory experiments)

WMM also explains findings from memory experiments that MSM cannot e.g. it can explain studies that show that individuals can carry out two STM tasks simultaneously and their performance is just as good as when they do the tasks separately. MSM does not explain this because, if STM is a single store, then two tasks should fill up the capacity of the STM more quickly compared to just doing one task.

fifth paragraph (baddeley findings and conclusions)

Evidence for this comes from Baddeley et al (1975), who showed that Ps could track a moving light with a pointer whilst carrying out a verbal task, but were unable to carry out the visual tracking task whilst doing another visual/spatial task which involved describing the angles in a capital letter. This was because both visual tasks compete for the limited resources of the visuo-spatial sketchpad. However, when doing one visual and one acoustic task separate WMM components were used (Phonological Loop & Visuo Spatial Sketch pad), and so provided the two tasks do not use the same component of the WMM they can be done equally well.

sixth paragraph (evidence for the phonological loop - baddeley experiment)

Evidence for the phonological loop comes from the Baddeley's et al. 1975 experiment. In this study pps were shown 2 lists of words: 5 short words + 5 long words. They recalled more short words accurately. He concluded that long words have more syllables and take longer to rehearse in ACS than short words, therefore long words are rehearsed less thank short words and stored less well in the phonological store. He called this the 'word length effect'. When a distractor task (la, la, la) was given it caused 'articulatory suppression' i.e. it prevented rehearsal of words by displacing them from the articulatory loop. Short words therefore had no advantage in terms of rehearsal, and this explains why they were remembered equally well to long words. This provides evidence that the PL has a limited capacity i.e the distractor task was competing for resources and displacing the words from the PS.

seventh paragraph (flashbulb memory)

WMM can additionally explain other observations which MSM cannot properly account for, such as flashbulb memories, which don't require rehearsal. The explanation is that the flashbulb memory goes straight to LTM via Central Executive. The MSM, however, cannot explain this finding because rehearsal is required to go from STM to LTM.

eighth paragraph (familiar words easily remembered)

WMM can furthermore explain why it is easier to remember list of familiar words rather than 'nonsense' words. The explanation is because the central executive / episodic buffer has a two way exchange with LTM, retrieving familiar words already in the LTM. The MSM is 'linear' and so doesn't explain this link with the LTM.

ninth paragraph (case study)

Finally, WMM explains the findings from 'KF' who could not remember digits that had been read to him but could remember them if he had been allowed to look at them himself. MSM cannot explain this because it has only one (unitary) store for STM. WMM, however, explains this because it separates stores for acoustic and visual information. KF probably had a damaged phonological store but an intact VSS - he was therefore able to recall information that he had seen but not that he had only heard.

tenth paragraph (weakness - central executive)

The WMM, however, does not offer a complete explanation for how memory works. For example, the exact role played by the central executive (CE) is unclear; it could be said that it is the same as 'attention'. There is no single part of the brain that is active when performing a 'CE' task and so the idea that the CE is a single component is questionable. It has been suggested instead that there could be entirely separate verbal and spatial working memory systems.