the WM model

• who developed the WM model


  baddeley and hitch, 1974
• why was the WM model developed


  developed in responce to the potential inaccuracies in the MSM as we can do two tasks at once

  - this would not be possible with the MSM if their idea of having a unitary store with limited capacity was true
• what is the WM model


  the model of memory which suggests that there are several components that make up the STM and they all take an active role in processing information
• differences between MSM and WM


  MSM: concerned with sensory store, STM and LTM

  WM: focus on STM only

  
  

  MSM: says that STM is a passive store, where info 'rests' before going to LTM

  WM: suggests that the STM is active

  
  

  MSM: sees the STM as a unitary store

  WM: sees the STM as containing multiple components and processes which work together
• what are the stores in WM


  central executive

  
  

  visiospatial sketchpad

  episodic buffer

  phonological loop - articulatory control system, phonological store
• what is the central executive


  responsible for a range of processes eg:

  - setting task goals

  - monitoring and correcting errors

  - starting reheasal processes

  -switching attention between tasks

  - inhibiting irrelevant info

  
  

  retrieving info from ltm
• coding of central executive


  can process info from any sensory modality
• capacity of central executive


  limited
• what is the phonological loop


  to hold words and rehearse any words that are currently being considered

  
  

  has 2 parts:

  phonological store

  articulatory process
• what is the phonological store


  holds the words you hear
• what is the articulatory process


  the verbal rehearsal system
• capacity of phonological loop


  2 seconds worth of information
• coding of phonological loop


  acoustic
• what is the visuospatial sketchpad


  deals with information by visually organising it and is concerned with pattern recognition and the perception of movement

  
  

  -colour/shape/arrangement
• capacity of visuospatial sketchpad


  3-4 objects (limited)
• coding of visuospatial sketchpad


  visual
• what is the episodic buffer


  connection between working and long term memory.

  
  

  - it also combines information in order to create an episode/a single memory

  - maintains a sense of time sequencing
• capacity of the episodic buffer


  limited, about 4 chunks
• coding of the episodic buffer


  modality free
• research evidence the phonological loop and its limited capacity (aims and method)


  Led by baddeley, to see if the length of the words affect the number of words you can recall

  
  

  Participants were shown 5 words briefly and then had to recal them in serial order with two conditions

  1) short words eg twice, harm, wit

  2) long words eg representative, association

  
  

  Participants did both conditions - repeated measures
• research evidence the phonological loop and its limited capacity (findings and conclusion)


  Findings:

  Participants could remember more words from the short word list compared to the long word list

  
  

  Conclusion:

  the findings suggest that the phonological loop has a limited capacity and it depends on how much can be said in approx 2 seconds- longer words take longer to say so will have less recalled
• research for multiple components in the WM and the effect of dual task performance (aims and procedure)


  baddeley et al, wanted to investigate the presence of multiple components in the WM with dual task performance

  
  

  procedure:

  Participants were given a visual task, to track a moving light and at the same time they were given one of two other tasks to complete simultaneously

  - task 1, to describe all angles on the letter F

  - task 2, to perform a verbal task
• why may dual task studies be used?


  to investigate how the performance of the initial task is affected depending on the second task given

  - baddeley and hitch suggested that the MSM's unitary idea of the STM would not allow for any multitasking which means that it must be incorrect because people can multitask
• research for multiple components in the WM and the effect of dual task performance (findings and conclusion)


  findings:

  participants found task 1 very difficult whereas they were able to track the light and do the verbal task 2

  
  

  conclusion:

  When two tasks use the same component it is difficult to do the task whereas using two different components is easier

  This suggests that there are separate components in the WM and they all have a limited capacity which cannot perform more than one task
• positive evaluation points of the WM (3 points)


  1) WM had more detail about STM than the MSM. It says that the STM is not a unitary store, had multiple components actively working together to process info

  
  

  2) Research evidence to support WM comes from dual task performance studies. These show that two tasks can be performed at the same time as long as they use different components

  - baddeleys study supports this

  
  

  3) Can be supported by case studies of amnesia patients eg KF

  - KF had a damaged STM verbally but visually was fine

  - with the knowledge of the WM, we can assume that it was his phonological loop was damaged but his visuospatial sketchpad was was in tact
• negative evaluation of WM (3 points)


  concept of the central exective is vague

  - we dont really understand how it works and there may be more than one component

  - Eslinger and Damasio studied EVR who had a brain tumor removed, he performed well on tests with reasoning which suggests his CE was intact but he had poor decision making skills which suggests his CE was not 100% intact

  
  

  lab experiments such as baddeleys dual task studies often lack ecological validity because they involve unfamilliar stimulus material

  
  

  the model fails to account for musical memory

  - we are able to listen to instrumental music without imparing performance on other acoustic tasks

  - this suggests the working memory does not offer a complete understanding of how memory works
• how has neuroimaging help evidence the WM


  it has provided some evidence for localisation of the different subcomponents of WM
• who evidenced the WM


  Pauesu et al
• how has neuroimaging proved localisation


  pauseu demonstrated diff areas of the brain were activated when doing tasks which required the phonological store and the articulatory rehearsal system

  
  

  - using a PET scan they found that brocas area was activated when a task needed to remember words and the supramarginal gyrus was activated when the phonological store was being used
• how has neuroimaging disproved the CE


  the exact location of the CE has been difficult to find as it largely diffuses across the cortex which suggests it may be more than one function
• what is the articulatory rehearsal system linked to in the brain


  brocas area
• what is the phonological store linked to in the brain


  supramarginal gyrus