The Working Memory Model (SL IB Psychology)

What is the Working Memory Model?

• The Working Memory Model (WMM) was devised by Baddeley & Hitch (1974) as a response to Atkinson & Shiffrin’s (1968) Multi-Store Model of Memory in terms of providing a more dynamic and flexible model of memory
• The WMM focuses on short-term memory (STM) only, there is no provision made for the functions or types of long-term memory in the model, it only aims to explain the ‘here and now’ of memory i.e. what you need to work for you in the current moment
• The WMM sees STM as a complex information processor rather than as a static unitary store
• The WMM is composed of four units:
  • the central executive (CM)
  • the phonological loop (PL)
  • the visuospatial sketchpad (VSS) with the
  • episodic buffer (EP) which was added much later on in 2000

The Working Memory Model

What is the Central Executive?

• The CE is the driving force of the WMM as it decides which tasks are to be assigned to which specific slave systems e.g. the VSS or the PL rather like the managing director of a company
• The CE is not so much a memory store but a ‘command centre’ as it plays a key role in controlling the processes of working memory
• Although the CE is probably the most important element of the WMM it is very difficult to test (unlike the VSS and the PL)
• The CE decides which information to pay attention to and which information to ignore and it then directs the slave systems to act accordingly

What is the Phonological Loop?

• The PL attends to and organises acoustic information in the form of spoken or written information (e.g. written words are encoded via vocalising or ‘speaking’, them in the mind so that visual information becomes acoustic information)
• The PL can be divided into two parts:
  • the phonological store and
  • the articulatory control system
• The phonological store is the ‘inner ear’ of the WMM as it processes and stores acoustic, speech-based information for a very short duration (a couple of seconds)
• The articulatory control system translates written words into speech so that they can then be kept in the phonological store in a kind of loop or ‘holding pattern’ so that we can gain access to it quickly, e.g. repeating a phone number over and over again until we can put it into our phone

What is the Visuospatial Sketchpad?

• The VSS attends to and organises visual and spatial information e.g. the colour of a flower, the arrangement of windows and doors in a house
• The VSS is used when you recognise a photo of your friend on social media for example or when you give directions to a stranger (e.g. How do I get to the train station?)
• The VSS can be divided into two parts:
  • the visual cache and
  • the inner scribe
• The visual cache is the ‘inner eye’ of the WMM as it stores information about form and colour (e.g. a purple triangle)
• The inner scribe contains spatial and movement-related information (e.g. how to get from one side of a crowded room to the other)
• The inner scribe rehearses information which is then stored in the visual cache

Your inner scribe is constantly responding to an array of visual stimuli…

What is the Episodic Buffer?

• The EB was added to the model in 2000 as a way of acknowledging that the CE has to communicate with LTM in order to be able to function effectively
• Our working memory needs access to the information stored in LTM to be able to respond to the current situation – not being able to remember which side of the road to drive on, for example, could cause all sorts of problems!
• The EB acts as a sort of messenger that communicates between LTM and the slave systems of the WMM
• The EB arranges information into ‘packets’ and, when the time is right, it moves this information to other slave systems in a way which makes sense for the individual and which follows a set sequence i.e. events occur continuously rather than seeming out of joint (e.g. if you are having a conversation you see the other person speaking at the same time as their lips move)

Which research studies support the WMM?

• Baddeley et al. (1973) – dual-task lab experiment provides support for the PL and VSS
  The case of KF
• (Shallice & Warrington, 1974) – the case study of a brain-damaged patient provides evidence of the PL and the VSS as separate slave systems

Baddeley et al. (1973) is available as a separate Key Study – just navigate the Cognitive Processing section of this topic to find it along with the Key Study for the Multi-Store Model of Memory (Two Key Studies of Models of Memory)

Evaluation of the Working Memory Model

Strengths

• The WMM provides a much more detailed and dynamic model of STM than the multi-store model of memory does as it explains how different processes in memory e.g. response to acoustic and visual information occur at the same time
• The WMM can be tested under controlled conditions such as those used in a lab experiment

Weaknesses

• There is very little insight or evidence as to how the CE functions in terms of directing attention towards the slave systems
• Not properly explaining the role of LTM in memory means that the WMM is limited and ignores key factors in the ways that STM and LTM combine to produce working memory