Memory - The Working Memory Model Flashcards
The Working Memory Model
- This is a representation of how STM is organised, proposed by Baddeley and Hitch in 1974 as an updated version of the STM
- It suggests that STM is an active processor of different types of information using sub units coordinated by a central decision making system as an extension of the MSM
- The WMM models the part of the mind that is active when we are temporarily storing and manipulating information
- It’s four main components are qualitatively different in terms of their capacity and coding
Why was the WMM created?
- Criticisms of the MSM’s depiction of the STM
- It was believed the STM must be more complex than just a single unitary store that only exists to pass information onto the LTM
- The STM must be an active processor, holding different types of information simultaneously while being worked on
The components of the WMM
- Central Executive
- Episodic Buffer
- Phonological loop
- Visuo-spatial sketchpad
The central executive
- The CE is a component of the WMM that coordinates the activities of the three sub-systems in memory and this has a supervisory function
- It monitors incoming data from the senses and the LTM, makes decisions and allocates the slave systems to tasks
- It also allocates processing resources to those tasks
- The CE has very limited processing capacity and cannot attend to many tasks at once and has no capacity for storing data
- It can process information from any sensory modality
The phonological loop
- This is the component of the WMM that processes information in terms of sound (acoustic coding) and preserves the order in which the information arrives
- This includes both written and spoken information and material
There are two subdivisions of the phonological loop:
- The phonological store - which stores the words you hear, like an ‘inner ear’
- The articulatory process - which is used for words heard or seen, and it allows maintenance rehearsal, and the capacity of this loop is believed to be 2 seconds worth of what you can say and so it has limited capacity; the ‘inner voice’ that repeats words and sounds in your head
The visuo-spatial sketchpad
- This is the component of the WMM that processes visual and spatial information in a mental space often called the ‘inner eye’ - visual information refers to what things look like, and spatial information is the physical relationship between things
- For example, if you are asked to work out how may windows are in your house, you visualise it
- It has a limited capacity of around 3-4 objects
- Logie (1995) subdivided the VSS into the visual cache and the inner scribe
1) Visual cache - stores visual data
2) Inner scribe - records the arrangement of objects in the visual field (spatial relations) - This slave system contributes to our understanding of visual semantics - the meanings of objects in our visual environment, and it can access our LTM store and retrieve visuo-spatial information e.g. if asked to think of something you can sit on, one can visualise a chair
The episodic buffer
- This was a component added by Baddeley in 2000 which brings together material from other slave systems into a single memory rather than separate strands i.e. it is a temporary store of information, integrating the visual, spatial and acoustic information processed by other stores as well as the CE and maintaining a sense of time-sequencing
- It records events (episodes) of what is happening
- It can be seen as a storage component of the central executive and has a limited capacity of about 4 chunks
- It also provides a bridge between working memory and LTM, sending the information to the LTM
The findings of the dual-task technique
- If one store is used for both tasks, then task performance is poorer due to the store’s limited capacity
- e.g. the phonological loop is used for both saying ‘the
cat’ aloud and reading, making the task difficult due to
limited capacity
- e.g. the phonological loop is used for both saying ‘the
- If the tasks require different stores, performance would be unaffected when performing them simultaneously
- e.g. drawing and reading use different stores = easy
Evaluation of the WMM - Supporting evidence
1) Shallice and Warrington’s (1970) case study was of a patient, KF, who had suffered brain damage. After this damage, KF had poor STM ability for verbal information, but could process visual information i.e. he had difficulty with sounds but recalled letters and digits shown to him
- This supports how the STM consists of different components that store different information; KF may have an impaired phonological loop but an intact visuo-spatial sketchpad, and so this gives the WMM external validity by showing that there are different components
- Suggests existence of separate visual and acoustic stores
2) Studies of dual-task performance support the existence of the visuo-spatial sketchpad. Baddeley et al (1975) found that participants had more difficulty doing two visual tasks (tracking a light and describing the letter F) than doing a visual and verbal task at the same time . This increased difficulty is because both visual tasks compete for the same slave system, whereas when doing a verbal task and visual task simultaneously, there is no competition
- This provides evidence for the model as it suggests different tasks and information are stored and recalled by distinct STM components, supporting the model’s suggestion of different STM stores; different slave systems to process the visual input (VSS)
Evaluation of the WMM - Supporting Evidence
3) Braver et al (1997) gave their participants a task that involved the central executive whilst having a brain scan - they found greater activity in the prefrontal cortex and that this activity increased as the task got harder
- This supports the role of the CE in allocating tasks to the slave systems, providing strong evidence for the idea of the STM activity being coordinated and information delegated to different components; as demands on the CE increase, it has to work harder to fulfil its functions, evidenced by this study
Evaluation of the WMM - Weakness
1) Cognitive psychologists suggest that the central executive is unsatisfactory and doesn’t really explain anything - Baddeley himself recognised that the central executive is the most important but least understood component of the WMM. It needs to be more clearly specified than just being simply ‘attention’ - for example some psychologists believe it may consist of separate components
- The model is therefore not able to provide a complex understanding of the evident importance of the CE, suggesting the model is not a fully extensive representation of the STM
- More development is needed on the concept of the CE; incomplete explanation
