Working memory model

• Central executive

  / l \

  Phonological Episodic buffer Visuospatial sketchpad

  loop
• Central executive-

  -Function is to direct attention to particular tasks, determining at any time how brains resources should be allocated

  -Acts as coordinator of all processes

  -Limited capacity
• Phonological loop -

  -Limited capacity

  -Responsible for storing verbal information as we hear it

  -Divided into 2 sections:

  >Phonological store- Holds words you hear or see

  >Articulatory process - Silently repeats words you have heard or seen
• Visuo-spatial sketchpad-

  -Limited capacity

  -Referred to as inner eye

  -Used when you need to plan spatial task e.g route from one room to another

  -Divided into:

  >Visual cache- stores info visual items e.g form and colour

  >Inner scribe- deals with spatial relations which stores the arrangement of objects in the visual field
• Episodic buffer-

  -Baddeley added it in 2000

  -An extra storage system that has limited capacity

  -Integrates information from central executive, phonological loop, visuospatial sketchpad

  -Maintains sense of time sequencing

  -Sends info to LTM

  -Holds visual and acoustic information
• Aim of Baddeley and Hitch -

  -To investigate if participants can use different parts of working memory at same time
• Method of Baddeley and Hitch -

  -Conducted experiment in which ppts were asked to perform 2 tasks at same time (dual task technique)- a digit span task which required them to repeat a list of numbers and a verbal reasoning task which required them to answer true or false to various questions
• Results of Baddeley and Hitch -

  -As number of digits increased in task, ppts took longer to answer the reasoning questions, but not much longer , only a fraction of a second

  -They didnt make any more errors in verbal reasoning tasks as the number of digits increased
• Conclusion of Baddeley and hitch -

  -Verbal reasoning task made use of central executive and the digit span task made use of phonological loop
• Strength of Phonological loop - Supporting evidence

  -Evidence comes from word length effect

  -Baddeley found people have greater difficulty remembering a list of long words compared to short words (word length effect)

  -Because of limited space for rehearsal in articulatory process

  -This effect disappears if ppt is given articulatory suppression task.

  -It means you are unable to repeat the shorter words more quickly than longer ones. Demonstrates articulatory process
• Criticism of Central executive - Too vague

  -Idea of central executive is too vague and "allocating resources" is essentially same as saying attention

  -Some believe it may consist of separate components and is not fully explained in WMM
• Strength of Central executive - Supporting evidence

  -Braver performed brain scans of ppts whilst they were doing tasks involving CE

  -They found that as the task became harder, activity in prefrontal cortex increased

  -Suggests CE may have some physical reality in brain
• Strength of WMM - Supporting evidence

  -Shallice and Warrington studied patient KF with brain damage

  -Noted his short term memory for auditory information had been greatly impaired compared to visual stimuli

  -His auditory problems were limited to verbal material such as digits and letters but not meaningful sounds

  -Was concluded his brain damage is limited to phonological loop