Working Memory Model (WMM)

Working Memory Model (WMM)

1. Central Executive

   • Directs attention to each of the slave systems
   • Very limited capacity
   • Bunge et al (2000)
     • Used fMRI to see which parts of the brain are most active when doing two tasks
       • Same areas of the brain were active when doing single and dual activites
         • Significantly more active during dual activities, suggesting more attention was needed

2. Episodic Buffer

   • Added by Baddeley in 2000
     • Realised the model needed a general store
   • Limited capacity
   • Integrates information from all of the components
   • Baddeley et al. (1987)
     • Participants were shown a list of words and then asked for immediate recall
       • Performed better when they were recalling sentences
         • Supports the idea of an immediate memory store for items neither visual nor phonological & drawn on long term memory

3. Phonological Loop

   • Deals with auditory information
   • Limited capacity
   • Baddeley (1986)
     • Phonological store
       • Holds the words you hear
       • Inner ear
     • Articulatory process
       • Used for words that are seen or heard, they are silently repeated
         • Form of maintenance rehearsal
       • Inner voice
   • Explains word length effect
     • Baddeley et al. (1975a)
       • People cope better with short words than long words in the working memory (STM
         • Seems phonological loop can hold information for 2 seconds
           • Longer words can't be rehearsed in the phonological loop as they don't fit

4. Visuo-spatial sketchpad

   • Logie (1995)
     • Visual cache (store)
       • Stores visual information
     • Inner scribe
       • Deals with spatial tasks
   • Baddeley (1975b)
     • Participants given a tracking task
       • Given one of two tasks to do at the same time as the tracking task
         • Task 1: describe all the angles on a letter
         • Task 2: performing a verbal task
         • Task 1 was harder than task 2
           • Suggesting that task 2 used a different component to the tracking task, whereas task 1 used the same component
   • Deals with visual and/or spatial information

5. Proposed by Baddeley and Hitch (1974)

   • Believed that short term memory was not just a single store
   • Working memory refers to the bit of memory you use when you work on a complex task, for example calculating a complex sum

6. Evaluation

   • Strengths
     • Comparisons with multi-store model
       • There is abundant evidence of the existence of a brief memory store
       • Offers a better account of the STM component than MSM
     • Different kinds of memory
       • WMM Represents a shift in our understanding of memory
         • We are now able to distinguish different types of memory, instead of considering it one activity
     • Explanatory power
       • Explains many psychological observations, including the word-length effect and the partial STM difficulties of brain damage patients
     • Supporting evidence
       • Considerable amount of supporting evidence
         • Especially with more recent studies
   • Limitations
     • Central executive
       • Damasio (1985) studied EVR
         • Had a brain tumor removed
         • Performed well on tests on reasoning, suggesting his central executive was still in tact, however he had poor decision making skills, suggesting his central executive was not wholly in tact
     • Evidence from brain damaged patients
       • Can not do 'before and after' comparisons
       • The event of getting brain damage is traumatic in itself , which might have caused the changes, not the damage

7. Case studies of brain damaged patients

   • LH (Farah et al 1988)
     • Performed better on spatial tasks than those involving visual imagery
       • Suggests separate visual and spatial systems
   • KF (Shallice & Warrington 1970)
     • Showed STM works seperately to LTM
       • Struggled remembering auditory information more than visual stimuli
         • Auditory problems were limited to verbal material such as letters, not meaningful sounds, eg. phone ringing
           • Suggests brain damage was restricted to the phonological loop
   • SC (Trojano & Grossi 1995)
     • Good learning abilities but couldn't learn word pairs that were presented out loud
       • Suggests damage to the phonological loop