Working memory model

• Working memory model - Baddely and Hitch (1974)

  Baddely and Hitch thought the STM was more complex than the MSM suggests. They suggested it was divided into several components.

  
• The Central Executive

  Has a supervisory role and directs attention to particular tasks.

  It does this by allocating tasks to the various subsystems.

  Very limited capacity, so can only attend to a limited number of things at a time.

  Can code information from any type of source
• Phonological loop

  Very limited capacity

  Stores limited number of speech based sounds (acoustic coding)

  Subdivided into phonological store (holds words we hear, inner ear) and articulatory process (silently repeating words you hear (inner voice)
• Visio-spatial sketchpad

  This is used when we have to plan a spatial task (visualise)

  Involves holding spatial and visual information (visual coding) and capacity is limited to about 4 objects.

  Seen as inner eye
• Episodic buffer

  Enables the central executive to access information in the LTM and integrate information in the other systems.

  Helps create a mental episode of what is experienced and maintains a sense of time sequencing.

  Limited capacity
• AO3 - real life tasks WMM

  WMM can explain why we can sometimes do two different things at once such as driving and talking as they involve two separate stores

  It can also explain why we can't, if we do two tasks at the same time with the same store then our performance will suffer.
• Automated tasks and working memory

  Capacity of all parts of working memory is limited. When we have to carry out a complex calculation in our heads we easily get confused because there is too much information to hold in working memory at once, so some of it may be forgotten if we cannot write it down
• Automated tasks

  The solution is to repeatedly practice tasks so often that they become almost automatic. These are known as automated tasks and do not require as much space in our working memory.

  This allows the central executive to devote capacity to other things
• Dual task performance

  The model predicts the it will be harder to do 2 things at the same time if they are both visual or both verbal tasks, because they will be using the same store at the same time.

  However if you are doing 2 things at the same time, one visual and one verbal then you could do these well as they use different stores
• Badly study - dual task performance

  Procedure - Gave all participants a visual task (tracking a moving light with a pointer)

  They were then given another task do to either a) imagining the letter F and explaining the angles or b) repeating words
• Badddley study findings

  Those who had to imagine the letter F had impaired performance but the who had to repeat words did not have their performance affected
• If we attempt to use the same subsystem for two tasks at once they will be in competition for its limited capacity and performance will be impaired, compared to using two different subsystems
• Strengths (AO3) Dual tasks experiments

  Baddley study supports the WMM that there are separate subsystems that process and visual and sound based information separately
• Strengths (AO3) Brain scans

  Study put participants in a fMRI scans and asked them to carry out different tasks. When the central executive was working, there was activity in the frontal lobe of the brain.

  The occipital lobe of the brain when the task was visual, suggesting task use different parts of the WMM
• Strengths (AO3) Case study of KF

  After KF accident he had a very poor STM for sound based information but normal STM for visual information, this supports the idea that there are separate parts in the WMM
• Weaknesses (AO3) - central executive

  Central executive is a very important part of the model but the model does not give enough information on how it allocates its resources. Some psychologists feel it is too vague to suggest it is attention and don't think it explains the role adequately
• Weakness (AO3) - central executive more components

  The model suggests there is a single central executive but there is evidence for several components.

  Case study EVR had a cerebral tumour removed and performed well on reasoning tasks but had poor decision making skills suggesting central executive may be complex and not a single entity