The Working Memory Model
The Working Memory Model was developed by Alan Baddeley and Graham Hitch in 1974 as an improvement on the multi-store model.
It explains short-term memory as an active system made up of several components that process different types of information.
Central Executive
The central executive is the main control system.
Functions:
Directs attention
Allocated tasks to other components
Coordinates mental activities
Has very limited capacity
It does not store information itself: it manages other systems
Example: Concentration on driving while listening to directions.
Phonological Loop
The phonological loop processes verbal and auditory information.
It has two parts:
a) Phonological Store
- Holds spoken words and sounds breifly
- Sometimes called the “inner ear”
b) Articulatory Process
- Repeats information to keep it in memory
- Sometimes called the “inner voice”
It uses acoustic coding and it’s capacity is limited (about 2 seconds)
Example: Repeating a phone number silently to yourself
Visuo-Spatial Sketchpad (VSS)
The visuo-spatial sketchpad stores and processes visual and spatial information.
Functions:
Menal images
Shapes, colours, locations, movement
The VSS uses visual coding and spatial coding, and it has a limited capacity.
Example: Imagining a route on a map or visualising furniture in a room.
Episodic Buffer
The episodic buffer was added later by Alan Baddely in 2000
Functions:
Temporarily stores integrated information
Links information from
- phonological loop
- visuo spatial sketchpad
- long-term memory
Creates a coherent “episode”
The episodic buffer uses multi-modal coding.
Example: Remembering a scene from a film by combining images, sounds, and meaning.
How the Components Work Together
The central executive controls attention
The phonological loop handles sound and speech
The visuo spatial sketchpad handles visual/spatial material
The episodic buffer combines information into a single experience
Evaluation (A03 Points)
Supported by dual-task research
One strength is evidence from dual-task studies.
Alan Baddeley found that ppts could perfrom two tasks at the same time more easily if the tasks used different components of working memory (e.g. a visual task and a verbal task).
This supports the idea that STM has separate systems rather than being a single store.
Evidence from brain-damaged patients
Studies of braim-damaged patients support separate components in working memory.
For example, patient Kenneth Warrington studied individuals with poor verbal short-term memory but normal visual memory.
This suggests the phonological loop and visuo-spatial sketchpad are separate systems.
Limited explanation of the episodic buffer
The episodic buffer was added later to explain how information is integrated.
However, there is less research evidence supporting it compared with the other components.
This means some psychologists question whether it is fully understood.
The central executive is vague
A major limitation is that the central executive is not clearly explained.
Alan Baddeley himself admitted it is the least understood component.
The model does not fully explain:
how it works
its capacity
how it control attention
This reduces this scientific precision of the model.