The working memory model
Overall
Baddeley and Hitch (1874) felt that short-term memory was not just one store, but a number of different stores.
This was because they believed:
If you perform two things at once (dual performance) and they are both visual tasks, you perform them less well if you do them separately.
If you do two things at the same time and one is visual and the other involves sound, then there is no interference. You can do them well simultaneously and separately.
Central Executive
Directions attention to particular tasks, determining at any time how the brain's resources are allocated to tasks.
Has a very limited capacity.
Data arrives from the senses or from long-term memory.
Phonological Loop
Has a limited capacity.
Deals with auditory information and preserves order of information.
Baddeley (1986) divided this loop further into:
The phonological store which holds the words you hear.
An articulatory process which is used for words seen or heard. These words are silently repeated, like a form of maintenance rehearsal.
Visuo-spatial Sketchpad
Used when you plan a spatial task (e.g. travelling)
Visual and/or spatial information is temporarily stored here. Spatial information is the relationship between things (e.g. a book on a table)
Logie (1995) suggested that the sketchpad can be divided into:
A visual cache which stores information about visual items (form // colour)
An inner scribe which stores the arrangement of objects in the visual field.
Episodic Buffer
Baddeley (2000) added this component to the WMM because he realised the model needed a store.
The phonological loop and visuo-spatial sketchpad deal with storing specific kinds of information.
The central executive has nowhere to store information that relates to both visual and acoustic information.
The episodic buffer is an extra storage system that has limited capacity.
It integrates information from the central executive, the phonological loop and the visuo-spatial sketchpad.
It also maintains a sense of time sequencing - recording events that are happening.
The information is sent to the long-term memory.