The Working Memory Model

The Working Memory Model

1. Baddeley & Hitch (1974)

   • Argued that STM was more complex
   • Instead saw STM as an active store
   • Proposed a multi-component working memory

2. Central Executive

   • Filter that determines which information is and is not attended to.
   • Processes information in all sensory forms, directs information to other slave systems and collects responses.
   • Limited in capacity
     • Can only cope effectively with one strand of information at a time.
   • Oversees and coordinates the components of working memory.
   • Located in the pre-frontal cortex
     • Pre-frontal cortex is activated when verbal and spatial tasks were performed simultaneously but not when seperately, suggesting that this brain area is associated with the workings of the CE.
       • D'Esposito et al. (1995)

3. The word length effect

   • Baddeley et al. (1975)
   • Partcipants recalled more short words in serial order than longer words, suggesting that the capactiy of the phonological loop is set by how long it takes to say words, rather than the actual number of words.

4. Strengths

   • It can account for findings of selective memory deficits, such as KF, that the MSM cannot.
   • Baddeley et al. (1998) have found that the phonological loop is important in reading, and that it is not operative in some children with dyslexia.
   • It can account for individual differences in memory processing and it has been shown that individuals can score highly on spatial working memory and yet low on verbal working memory and vice versa.
   • Has been applied to real life settings; because there is such a high correlation between working memory span and performance on various tasks. It has been used as a measure of suitability for certain jobs.
     • Kyllonen & Christal, 1990, investigations to use WM as a recruitment tool for the US air force.
   • Research support comes from dual-task studies (Gathercole and Baddeley 1993)
   • Supported by studies involving brain scans. PET scans have shown that different areas of the brain are used whilst undertaking visual and verbal tasks.

5. Limitations

   • The exact role of the central executive remains unclear, and some researchers have questioned whether it can be a single component.
   • Berz (1995) has criticised the model for failing to account for musical memory; we are able to listen to instrumental music without impairing performance on other acoustic tasks.
   • Much research comes from laboratory studies which are artifical and lack mundane realsim and ecological validity.
   • The capacity of the central executive has never been measured.
   • Doesn't explain changes in processing ability that occur as a result of practice or time.

6. Phonological Loop

   • Deals with auditory information and the order of information.
   • Slave system - temporary store dealing with different kinds of incoming sensory information.
   • Similar to the rehearsal system of the MSM with a limited capacity determined by the amount of information spoken out loud in about two seconds.
   • Primarily an acoustic store, confusions occur with similar sounding words.
   • Divided into two sub-parts: the phonological store and articulatory control system.
     • Phonological Store
       • 'Inner Ear'
       • Stores words heard
     • Articulatory Control System
       • 'Inner Voice'
       • Allows sub-vocal repetition of information

7. Visuo-Spatial Sketchpad

   • 'Inner Eye'
   • Handles non-phonological information.
   • A temporary store for visual and spatial items and the relationship between them.
   • A store for what items are and where they are located.
   • Information is rehearsed and encoded through the use of 'mental pictures'.
   • Helps individuals to navigate and interact with their physical environment.