Working Memory Model

• who suggested a more complex and dynamic STM than the MSM?

  Baddeley and Hitch (1974)
• what are functions of the WMM?

  • has several, but connected parts that can do different things simultaneously
  • however, two of same type would result in poor performance
  • is an active system, allows us to work things through
  • has little capacity
• what is the WMM composed of?

  • Central Executive
  • Visuospatial Sketch Pad (subdivided into Visuo-Cache and Inner Scribe - later added by Logie)
  • Episodic Buffer
  • Phonological Loop (subdivided into Articulatory Control System and Phonological Store)
• how does the WMM see the LTM?

  as a more passive store that holds previously learnt material for use by the WMM when needed
• what is the central executive?

  • in charge of reasoning and decision-making
  • has limited capacity - holds it for a short period of time until it has determined how the resources are allocated to what slave systems
  • selects strategies - can only do a number of things at the same time, will collect information from a number of sources such as inner ear, eye and info in LTM, and decide how to use it
• what is the phonological loop?

  • deals with auditory information and preserves word order - your 'inner ear'
  • has limited capacity - 2 seconds worth of information
  • Baddeley (1986) subdivided into phonological loop (holds words heard) and articulatory process (holds words heard/seen and silently repeating (looped))
• what is the visuospatial sketch pad?

  • where visual and/ or spatial information stored here - inner eye
  • also stores the relationships between things (spatial awareness)
  • has limited capacity, 3-4 objects
  • Logie (1995) suggested subdivision: visuo-cache (store), inner-scribe (for spatial relations)
• what is the episodic buffer?

  • holds most recent, activated memory from the LTM, so the episodic buffer is the LTM link
  • has limited capacity of 4 chunks
  • integrates information from all other areas, also keeps track of time so we have a sense of chronology so that everything in different stores can come back together in the right order
• what evidence is there for the WMM?

  • Baddeley and Hitch devised the dual-task technique (1976)
  • say a continuous list of random numbers (or continuously saying 'the' - occupies articulatory loop) whilst completing a true/false exercise
  • results show that two tasks that use the same component of memory causes difficulty, when different components are used, performance on tasks is not adversely affected
• what does the WMM suggest about STM?

  that it is not a unitary store, and has many components (this is an improvement on the MSM)
• describe the study of patient KF:

  • Shallice and Warrington, 1970
  • KF was involved in a motorcycle accident
  • he can't recall long-term memories
  • had normal ability to process visual information in the STM, but STM was limited as he had difficulty in dealing with verbal information
  • this suggests his phonological loop was damaged, but other areas of his WMM remained intact
• describe dual tasking by Baddeley in 1975:

  • demonstrated that when participants were given a visual task (tracking a moving pointer light) certain tasks will be more difficult to complete simultaneously
  • Task 1: describe angles on a letter 'F' while following the light
  • Task 2: a verbal task
  • Task 1 was more difficult to complete simultaneously as it overloaded the visuospatial sketch pad, whilst Task 2 separated 'slave systems' and can be carried out simultaneously
• who used brain scanning to see evidence of the central executive?

  Braver et al. (1997)
• what did Braver et al. (1997) do?

  • gave tasks which engaged the central executive whilst they were given brain scans
  • found there was greater activity in left prefrontal cortex - likely to be the brain region associated with the central executive
  • as the tasks became harder, the activity in brain region increased - as demands on the central executive increased
  • brain scanning techniques which showed engaged 'slave systems' activate different areas of the brain, demonstrating physical representations of components of the WMM
• describe dual tasking by Bunge et al. (2000)

  • used fMRI to see which parts of the brain were most active when participants were doing two tasks
  • the same areas (pre-frontal cortex) were active in dual or single task conditions, but were significantly more activated in dual task conditions - shows a higher demand for central executive
• what did Paulesu et al. (1993) do?

  • showed dual-task difficulties
  • also that the phonological loop may be further split (different locations for the articulatory loop and the subvocal rehearsal system)
• how is lack of clarity of central executive a limitation of the WMM?

  • the role is unclear
  • it is argued the CE is not a unitary store - Eslinger and Damasio (1985) studied a patient known as EVR who had a brain tumour, they performed well on reasoning tasks, but not on decision-making tasks
• how is research flaws a limitation to the WMM?

  • causation - clinical studies arise from brain-damaged patients who have sustained a traumatic injury which itself may be cause of behavioural change (unlinked to memory)
  • based on highly controlled lab studies - can't generalise to real world scenarios, this may undermine validity of the WMM