WMM

• Working memory model (WMM)

  Baddeley and Hitch 1974

  They argued that MSM was too simple in explaining STM. Their research showed that WM is not a unitary system but instead info goes into different systems for different types of info.

  WMM has a CE with components of PL and VSS.
• Working memory model

  
• WMM- CE


  Central executive:

  - Drives the whole system (acts as the boss)

  - Allocates info to the subsystems (and relation to LTM)

  - Deals with cognitive tasks such as mental arithmetic and problem-solving

  - The most important component but little is known

  - Decides what is paid attention to and gives priority to different activities over others

  - Selectively attends to some stimuli and ignores others

  - Can only do a limited number of things at the same time so uses support from subsystems
• WMM- VS


  Visuo-spatial sketchpad:

  - Stores and processes info in a visual or spatial form

  - Known as the inner eye and used for navigation

  - Helps us keep track of where we are in relation to other objects as we move through our environment

  - As we move, we update this info regularly in relation to objects and space

  - The sketch pad displays visual info held in LTM

  - An image is retrieved from LTM and pictured in STM
• WMM- PL

  Phonological Loop: (2 main parts)

  - Deals with spoken and written material

  
  

  Phonological store:

  - Acts as inner ear and holds information in speech for 1-2 seconds

  - Spoken words enter directly

  - Written words must be converted into articulatory code before it enters this store

  
  

  Articulatory control process:

  - Acts as inner voice rehearsing info from PS

  - Circulates info round a type loop

  - As long as we keep repeating it, we retain info in WM

  - Converts written material into articulatory code and transfers to the PS
• WMM- EB


  Episodic Buffer:

  - Acts as a backup store which communicates with LTM and WM

  - Carries out a large variety of processing activities

  - provides temporary storage in a multimode code so it communicated with slave systems and LTM

  - Added part of CE, acts as buffer between WM parts
• Evaluation of WMM


  Strengths: neuroimaging, dual-task studies (VSS and PL)

  Weaknesses: Critics, little evidence, reductionist
• WMM- Strength: Neuroimaging


  PET scans have shown when tasks use different sub-components of WM different parts of the brain are activated.

  Eg, when remembering words, Broca's area is activated but when using PS, the supramarginal gyros are activated.

  Suggests that the PL and VSS are separate from each other.
• WMM- Strength: Dual-task studies (VSS)


  Baddeley and Hitch 1976:

  - Demonstrated the existence of VSS by using a dual-task experiment

  - They asked participants to do 2 tasks that would utilise the VSS either same time or separately

  - They found that participants could perform the task well separately but when they did it together, performance was impaired

  - If they were asked to perform one of the tasks at the same time as a verbal, they were just as good as alone

  - This suggests that when undertaking 2 visual tasks, they compete for the limited resources of the VSS

  - This supports its existence
• WMM- Strength: Dual-task studies (PL)


  Baddeley et al 1975:

  - Existence of PL with word length study

  - Baddeley found that participants could remember more single syllable words than multi syllable ones

  - Word length effect

  - They were prevented from rehearsing the words which meant that word length effect disappeared as they were unable to use their PL for remembering words (as it was engaged in ACP task)
• WMM- Weakness: Critics


  Liberman 1980:

  - The VSS implies all spatial info was first visual

  - He pointed out that blind people have excellent spatial awareness although they have never had any visual info

  - He argued that VSS should be separated into 2 different areas for visual and spatial info
• WMM- Weakness: Reductionist


  - WM only involves STM and does not explain LTM

  - It does not explain changes in processing ability that can occur as a result of practice or time

  - There are other theories which can better explain it
• WMM- Weakness: Little Evidence


  Little direct evidence for the CE:

  - The capacity of CE has been measured but there is little evidence for its existence

  - The nature to investigate is very hard as it cannot be measured directly and the function has to be inferred from performance of tasks

  - It is impossible to design a task that effectively tests the CE without also affecting the slave systems

  - The CE may never be adequately investigated and will remain a concept