Working Memory Model
Central Executive - drives the whole system, very limited capacity. Functions to direct attention and resources. It has a supervisory role as when data arrives it allocates into two the two slave systems.
Phonological Loop - Limited capacity, deals with auditory information and preserves word order.
- Brady further divided it;
. Phonological store - hold words heard for 1-2 seconds
. Articulartory process - holds words seen/ heard and silenlty repeated like an inner voice, as a kind of maintinance rehersal.
Episodic Buffer - Baddely added it in 2000 as he realised it needed to be a more general store. central executive has no storage capacity, PL and VSSP deals with specific types of information.
Visuo-Spatial Sketchpad - Limited capacity, visual and/ or spatial information processed and stored in the inner eye.
. Visual - appearance
. Spatial - position/ location - relationships between things
LTM - information then is stored in long term memory.
Evidence to Support WMM
Baddeley et al (1976) - the dual task experiment
Shallice & Warrington (1970) - KF: involved in a motorcycle accident
Findings - Task 1 was difficult as it involves two visual tasks, but task 2 was easy because the second task involved two different slave systems (visual & verbal).
Conclusion - This dual task study provides evidence for separate visual and verbal slave systems in WM because performance is affected by whether the tasks complete for the limited resources of the same or different slave systems.
Procedure - pps were given a visual tracing task (track a moving ligth with a pointer), at the same time they were given one of two tasks. Task 1 - describing all the angles in the letter F, task 2 - was to perform a verbal task.
Findings - Shallice and Warrington found that KF's impairment was mainly for immediate recall of words presented verbally (auditory information).
Conclusion - WMM is a better explanation because it has more research, more component and is more dedicated.
Procedure - The case of KF: suffered brain damage after a motorbike accident.
SCOUT
❌ Other Explanations - The original model was that it didn't explain evidence from verbal span experiments that verbal and visual encoding could be combined. The model could not explain how the subcomponents could interfere with each other or with LTM. Baddeley addressed this in 2000 with the addition of a fourth component called the episodic buffer. The episodic buffer was proposed as a limited capacity storage system the could intergrate infomation between the subcomponents and feed into and retrieve infomation from LTM.
❌ Challenging Evidence - The exact location of the central executive in the brain has been difficult to find and it is thought to be largely diffuse across the cortex.
✅ Supporting Evidence - Neuroimaging: research has been carried out in different regions of the brain and have looked to the phonological store and articulatory loop. PET scans fund that Broca's area activated when the phonological store was being used.
This provides evidence for the phonological loop and it's separate subcomponents.
✅ Testable - Their is a lot of research to support WMM, e.g. lab studies, case studies and brain scans.
Helps us to understand real life examples such as Alzheimer's.
✅ Usefulness - Patients suffering from Alzheimer's disease has shown decreased central executive function as the disease has progressed. performing a visual or verbal task but showed significant impairment when trying to do them together, this impairment in performance demonstrates significant problems with executive functioning.