Working Memory Model

• Working Memory Model: 1

  • Developed by Baddeley & Hitch (1974), after seeing flaws in the Multi-store Model- the Working Memory Model focuses on STM.
  • They tested using a 'dual task' technique, to test if digit span was really a measure of STM capacity, by deducing that PPs would show impairment on the reasoning task, as the STM would be fully occupied.
• Working Memory Model: 2

  • Conclusion: STM must have more than one component & must be involved in other processes other than just storage, eg reasoning, understanding, learning.
  • Two tasks can be done simultaneously, as long as they are dealt with by different parts of the memory system.
  • LTM is a passive store that maintains previously learned info, for use by STM when needed.
• Working Memory Model:

  1. Information in Central Executive- can go to either Visuo-spatial Sketchpad, Episodic Buffer or Phonological Loop.
  2. The Episodic Buffer is in the middle and links all systems together.
  3. From the Episodic Buffer, information can either go into LTM, Phonological Loop or to the Visuo-Spatial Sketchpad.
• Central Executive:

  • Multi-codal.
  • Limited capacity.
  • Has overall control (supervisor).
  • Starts rehearsal, reasoning, decision making.
• Visuo-spatial Sketchpad:

  • Inner scribe (inner eye)- spatial relations, arrangement of objects.
  • Visual cache (passive store).
  • Visual, limited capacity.
  • Temporary storage holds visual/ spatial information.
• Episodic Buffer:

  • Multi-codal
  • Limited capacity
  • Can bind info from other areas, including LTM.
• Phonological Loop:

  • Articulatory control system/ loop (inner voice)- active/ maintenance rehearsal.
  • Phonological store (passive storage).
  • Limited capacity.
  • Auditory.
• Evaluation for WMM- Strength:

  • KF suffered damage to his STM following a motorcycling accident.
  • Situation wasn't quite that simple, since KF could still recall visual information using his STM, but struggled with auditory & verbal information, making conversation difficult.
  • KF's situation supports the ideas of the WMM, yet contradicts the Multi-store Model of Memory.
• Evaluation for WMM- Weakness:

  • Case Study of the patient EVR- who had a cerebral tumour removed and showed his Central Executive was effected, as he could perform reasoning tasks, but performed poorly on decision making tasks- these are both roles of the Central Executive, suggesting that it should not be just one component.
  • EVR's case study criticises the Central Executive, as it suggests it needs to be broken down more.
• Evaluation for WMM- Weakness:

  • There's further research that contradicts the WMM.
  • We are able to listen to instrumental music without it impairing other acoustic tasks (Berz 1995)- suggests that the Phonological Loop should be split into 2 areas: one for language & one for music.
• Evaluation for WMM- Strength:

  • The Working Memory Model attempts to explain both function & structure.
• Phonological Loop/ Articulatory Loop Procedure: 1

  • Visual presentations of word lists (rather than reading them out) & PPs asked to remember them & write them down in order.
  • 1st Condition: they were familiar, simple 1 syllable words, eg harm, cat, wit.
  • 2nd Condition: they were words of many syllables, eg organisation, accumulation, university.
  • Findings: short words were better recalled, so capacity of the 'loop' was determined by length of time to say/ read a word rather than number of individual items. This time limit was said to be 1.5 seconds.
• Phonological Loop/ Articulatory Loop Procedure: 2

  • Conclusion: your articulatory processes can rehearse short words quicker, therefore more time before recall, ie capacity is limited by short duration.
  • Evaluation: well controlled in lab, with each PP sitting both conditions so no individual differences to effect results (repeated measures), but it could have been that the longer words were just less familiar than the short ones, so harder to remember.
• Central Executive Limited Capacity- Hunt 1980: 1

  • Aim: to investigate evidence for a limited capacity Central Executive.
  • Method: repeated measures design (all PPs experienced both conditions). PPs performed a psychomotor task- gliding a lever between 2 posts with only the use of thumb & index finger, & at the same time completed an intelligence test consisting of spatial patterns.
  • Results: evidence that both tasks were making use of the same central processor (rather than sub-components) & both were competing for the same limited capacity available.
• Central Executive Limited Capacity- Hunt 1980: 2

  • Evaluation:
  • -Weakness: lacks ecological validity, PPs asked to perform 2 concurrent tasks that are not likely to take place together in the real world.
  • -Weakness: implied that the 2 tasks are using one central component, but it could be that the visuo-spatial sketchpad is in use.
• Visuo-spatial Sketchpad Evidence- Baddeley et al 1973: 1

  • PPs asked to follow a spot of light as it moved in a circular path, whilst carrying out a visual imaginary task simultaneously (looking at an angular block capital, eg H,T,F,O).
  • They had to hold image in their heads then, starting at the bottom left hand corner, to respond to each angle as a 'yes' if it included the bottom or top line of the letter & 'no' if it did not.
  • Findings: PPs found both at the same time very difficult.
• Visuo-spatial Sketchpad Evidence- Baddeley et al 1973: 2

  • Conclusion: difficult as both were competing for space in the limited visuo-spatial sketchpad.
  • Evaluation:
  • -Strength: very well controlled in lab & repeated measures.
  • -Weakness: very artificial, ie lacks ecological validity.
  • -Strength: ethics, was a debrief to confirm it was normal to find this task very difficult.