AS Psychology: The Working Memory Model
In the AS Unit 1 psychology exam 'Cognitive Psychology, Developmental Psychology and Research Methods' you will have to use evidence to compare the Multi-Store Model of Memory and the Working Memory Model. This article should include everything you need to know for the exam!
The Working Memory Model (WMM) is a model that represents one aspect of memory —short-term memory (STM) or immediate memory.
The model refers to the part of the memory that you use when working on a complex task which requires you to store and remember information as you go.
Baddely and Hitch proposed the WMM in 1974 as an alternative to the Multi-Store Model of Memory (MSM), as they thought the MSM was too simplistic and didn't think that the idea of the STM being a unitary store was correct.
Baddely and Hitch built the WMM on the idea that if you perform two visual tasks simultaneously then you perform them worse than if you do them separately whereas if you perform one visual and one acoustic task simultaneously there is usually no interference.
This suggests that the STM is split into different stores — one for visual processing and one for sound processing.
The Four Components of the WMM
The Central Executive:
- This is the main component of the WMM.
- Data arrives either from the senses or from the Long-Term Memory (LTM) and then the central executive acts as a conductor and directs the attention to particular tasks and allocates data to the different slave systems.
- The central executive has a very limited capacity and can't do too many things at once.
The Phonological Loop:
- The Phonological Loop is subdivided into two parts - The Phonological Store and the Articulatory Process.
- The Phonological Store, or 'inner ear', holds information in speech based form and allows acoustically encoded items to be held for a brief period of time.
- The Articulatory Process, or 'inner voice', allows sub-vocal repetition of items stored in the phonological store. This is a form of maintenance rehearsal.
The Visuo-Spatial Sketchpad:
- Also known as the 'inner eye', this component of the WMM is used when you have to mentally plan a spacial task (like getting from one room to another).
- It stores visual and spacial information and is also responsible for setting up and manipulating mental images.
- It has a limited capacity and much like the Phonological Loop it is subdivided into two parts, the Inner Scribe and the Visual Cache (Store).
- The Visual Cache deals with the storage of information.
- The Inner Scribe acts as a rehearsal mechanism.
The Episodic Buffer:
- In 2000 Baddely added the Episodic Buffer to the components of the WMM because he realised that the model needed a general store.
- The Phonological Loop and Visuo-Spatial sketchpad deal with processing/storage of specific kinds of information (acoustic, visual etc.), but because the Central Executive has no memory storage capacity the model needed a store that could deal with different types of information.
- The Episodic Buffer has a limited capacity and integrates information from all the components of the WMM and also the Long-Term Memory.
Shallice and Warrington conducted a case study in 1970 into a person known as 'KF'. KF had brain damage and could process visual information without any problems but could not process acoustic information in the form of letters and numbers, however he could process meaningful acoustic information (such as his phone ringing).
He also had no problems with his long-term memory but his immediate short-term memory seemed to be impaired. This showed that his brain damage seemed to be restricted to his Phonological Loop, and thus the validity of Baddely and Hitch's Working Memory Model was increased.
Bunge et al conducted an experiment in 2000 in which an MRI scanner was used to see which parts of the brain were most active when participants were performing a single task and also two tasks at once.
There was significantly more activity in the brain when two tasks were being performed indicating that there was an increased demand for attention when performing two tasks simultaneously.
This is evidence supported the existence of the four different components of the WMM.
Strengths and Weaknesses
- There is significant research evidence (such as the evidence above) to support the WMM.
- It is more complex and realistic than the previous Multi-Store Model of Memory, and it also emphasizes the processes involved in short-term and immediate memory rather than the structure.
- Some psychologists feel that the Central Executives job of allocating data is too vague and doesn't really explain anything.
- Critics also feel that the Central Executive should be split into several components.