WMM AO1

Working Memory Model (Baddeley & Hitch 1974)

• WMM is short-term memory, which has different systems for different types of information

• Replaces the STM in the MSM

• Central Executive —>

  • Visuospatial Sketchpad

  • Episodic Buffer

  • Phonological loop

• —→ Long-term memory

Central Executive

• Drives the system and decides how attention is directed by allocating resources to the ‘slave systems’

• Has no permanent storage capacity; has a limited capacity so cannot attend too many things at once

• E.g. two activities sometimes come into conflict, such as driving and talking. Rather than hitting a cyclist who is wobbling all over the road, it is preferable to stop talking and concentrate on driving. CE directs attention and gives priority to particular activities

Bunge (2000) in support of CE

• Experiment in which an MRI scanner used to see which parts of the brain were most active when pts were performing a single task and also 2 at once

• Significantly more brain activity when two tasks being performed, suggesting there was an increased demand for attention when performing two tasks simultaneously

Visuospatial Sketchpad (Slave sys #1)

• VSS (inner eye) deals with visual and spatial information. It has a limited capacity.

• Holds visual (what things look like) and spatial (relationship between things) information for a very short time

• Logie (1995) divided it into 2:

  • Visual cache: Stores visual information

  • Inner scribe: Records arrangement of objects

Gathercole & Baddeley (1993) - Support for VSS

• Pts had difficulty simultaneously tracking a moving point of light and describing the angles on a hollow letter F, as both tasks required the use of VSS

• Other pts had little difficulty in tracking the light and performing a simultaneous visual task, as both involve the VSS and PL, indicating the VSS to be a separate slave system

Brookes (1968) - Support for VSS

• Pts had to mentally visualise a letter (e.g. K) and were asked questions about is e.g. ‘Does it contain right angles?’

• They had to either speak aloud, tap or point to a yes/no sign to respond. It was found that the response was faster when it was spoken or with the tapping, (not visual) indicating they have the same limited capacity component

Phonological loop (slave sys #2)

• Deals with auditory information and the order of it. It has a limited capacity

• PL split into 2:

  • Phonological store (inner ear): A store of words heard

  • Articulatory control process (inner voice): Allows for rehearsal of heard words, so that they stay in your memory

Baddeley (1975) - In support of PL

• Found pts recalled more short words in serial order than longer words

• Supports idea that the capacity of the PL is set by how long it takes to say words rather than number of words recalled

Episodic Buffer (slave sys #3)

• Developed by Baddeley (2000) and updated the WMM

• Temporary store that links LTM with general storage space for both acoustic and visual information

• Integrates visual, spatial and verbal information from the CE, PL, VSS and LTM

• Has a limited capacity

Alkhalifa (2009) - Support for EB

• A patient with severely impaired LTM demonstrated an STM capacity of up to 25 items.

• Far exceeds capacity of both PL and VSS, so we need a buffer for this