Evaluating the working memory model

How does evidence from HM’s case support the WMM?

• His hippocampus was removed due to his epilepsy.

• His spatial memory was affected, verbal memory was unaffected.

• Supports the idea that there are sub-systems in the working memory

• Gives the WMM credibility.

How does KF’s case support the WMM?

• KF got into a motorcycle accident and his STM was damaged.

• He could process/encode visual information, but not verbal, his LTM was still intact.

• He could recognise meaningful sounds such as the phone ringing.

• Him being able to encode visual info but not verbal shows that there are distinct stores in the working memory.

• Gives the WMM credibility.

What is a PET scan?

• Involves patients being injected with fluorodeoxyglucose (FDG) which is a radioactive tracer.

• It attaches to glucose as this is what the brain uses for energy.

• A task is given to people placed in a scanner and when the glucose is used, the atoms breakdown to emit positrons.

• Resulting gamma rays are then picked up by the scanner reflected as different colours.

• High activity areas produce more gamma rays and show up as red/orange

• Less activity areas show up as blue.

How, through the use of brain imaging have parts of the WMM been found to be linked to specific brain regions?

• The phonological loop seems to be located in the left hemisphere - specifically the temporal lobe.

• VSSP in the right hemisphere - simple tasks in the occipital lobe, complicated tasks in the parietal lobe.

• Episodic buffer seems to be in both hemispheres (bilateral) - but specifically in the hippocampus (links to Schmolck study)

• Central executive seems to be linked to the frontal lobes.

What is neuropsychological evidence using PET scans for linking the WMM to specific brain regions?

• The use of PET scans allow us to look at which parts of the brain are activated when certain parts of memory ae used.

• Paulesau (1993) demonstrated that different areas of the brain are used when undertaking tasks that use the phonological store and articulatory store.

• The Brocas area is used when a task is given that requires you to remember words - articulatory process

• The supramarginal gyrus is activated when the phonological store is being used.

• Occipital lobe for visual tasks - VSSP.

How does Paulesau (1993) support the WMM?

• Supports the WMM as it shows links to biological structures giving it credibility.

• Parts of memory are a result of nature and is pre-programmed within us as we are born with these structures.

• This evidence demonstrates that memory is a result of nature, is biological, someone’s memory should work in the same way as anyone else around the world.

• Only thing that changes is our experience with memory which is nurture e.g. Clive’s memory only changed when he got ill.

How does the use of brain scans make research into the WMM scientific in terms of objectivity and control?

• There is no way that a researcher or Pp can consciously control their brain activity that is seen when in a PET scanner.

• The changes in activity that we see must be a true representation of what is happening in the brain.

• Therefore this method is OBJECTIVE, VALID, SCIENTIFIC.

• Consequently there is scientific evidence to support the WM being made up of different stores.

• We can actually see them working in different parts of the brain.

• Strength of the methodology as we can use this evidence to suggest that the WMM is correct.

How does the use of brain scans make research into the WMM scientific in terms of empiricism.

• We can provide people with different tasks to do that use one or multiple components of the WMM - and watch what happens in the brain whilst in a PET scanner.

• This means that we can produce SCIENTIFIC AND VALID evidence for the WMM as we can directly observe changes in the brain.

• PET scans are valid as we can directly see the changes.

What are dual task studies?

• There have been several dual task studies conducted to demonstrate that the WMM is correct and that there are subcomponents.

• Dual task studies are when the Pp are required to do two things at once which either occupy the same components or two components simultaneously.

What is Baddeley & Hitch’s (1976) dual task study?

• Conducted an experiment where Pp had to simultaneously use a pointer to track the location of a moving light on a screen while imagining the capital letter ‘F’, and mentally tracking the edges of the letter and verbally saying whether the angles they imagined were at the top or the bottom of the image.

• Pp could easily complete each task separately but had difficulty preforming the tasks simultaneously.

• This shows how two visual tasks both compete for the limited resources of the VSSP - resulting in impairment in performance.

• However when Pp were asked to perform the visual tasks while undertaking the verbal task at the same time, performance was not affected.

• Because one task used the VSSP and the other the phonological loop.

How does Baddeley & Hitch’s (1976) study offer support for distinct stores?

• Dual task experiments offer support for separate visual and verbal slave systems because performance is affected by whether they compete for the limited resources of the same or different slave systems.

What are the overall strengths for the WMM?

• The model has application value - we can use it in the real world to help with memory.

• When revising for exams you need to use visual methods and verbal methods to strengthen the memory trace.

• When tasks use both memory systems simultaneously, memory wont be as good.

• The inner eye and inner ear have face validity.

• Experimental evidence agrees with neuropsychological evidence.

• There are multiple examples of research to support the slave systems - however dual tasks due not have good external validity so it can be a weakness.

• The WMM focuses on memory process whereas the MSM focuses on structure (can also be a weakness.)

What are the overall weaknesses for the WMM?

• The central executive and the episodic buffer are less researched - decreases credibility.

• Dual task studies lack mundane realism and ecological validity.

• Still no acknowledgement of LTM - reductionist.