Working Memory model Flashcards
What does the central executive do?
Central executive
* Controls activity of working memory in two components
* Manages other two components,- Phonological loop and visuospatial sketchpad
* Its function is to direct slave system attention to particular tasks
* Determines how the other parts of the model are used and has the capacity to focus, divide and switch attention
* Very limited capacity
Modality free (Deals with info from all senses)
What is the phenological loop?
The Phonological Loop (Inner Ear)
This is what we call a ‘slave system’
Deals with auditory/ verbal information
Also limited capacity
What is phonological store?
The Phonological Store-
Holds words you hear (difficulty when words sound the same – acoustically similar)
What is articulatory process?
The Articulatory Process-
Used for words that are seen and heard (difficult when words are long)
These words are silently repeated (looped) which is a form of Maintenance Rehearsal.
What is the Visuo-spatial sketchpad?
This is also a slave system in the model and is used to manipulate visual and spatial information (inner eye)
It can deal with information directly through images or retrieve information from LTM
Used when you have to plan or complete a spatial task (for example, when getting from one place to another)
Visual/ spatial information is temporarily stored here
What is episodic buffer?
Baddeley 2000
Holds visual and auditory info
More general store as other two are too specific
Extra storage system but has limited capacity
Integrates info from all areas including LTM
What is evidence for phenological loop?
Baddeley, Thompson and Buchannan (1975) investigated what is known as the ‘Word Length Effect’
If there is a phonological loop that lasts for about 20-30 seconds then it would make sense that it could store more single syllable words (short words) than it could multi-syllabic words (long words) as it takes longer to say multiple syllables than it does a single syllable.
Baddeley et al found that participants could indeed remember more single syllable words than multi-syllablic ones, and they called this the word length effect.
However when they were prevented from rehearsing the words (by giving them an interference task that creates articulatory suppression, such as counting backwards in threes) the word length effect disappeared as they were unable to use their phonological loops for remembering the words because it was engaged in the articulatory suppression task.
This provides strong evidence that the phonological loop exists
What is evidence for visuo-spatial sketchpad?
Baddeley & Hitch (1976) demonstrated the existence of the visuo-spatial sketch pad by using a dual task paradigm.
In this they asked participants to do two tasks that would utilise the visuo-spatial sketch pad either separately or at the same time.
One task was to use a pointer to track a point of light moving around a screen, and the other task was to imagine a capital ‘F’ and mentally move round the edge of the letter classifying the angles as either belonging to its top or bottom.
They found that participants were able to perform the tasks separately without any difficulty, but when they did them together their performance at both was impaired. If they asked them to do one of the visual tasks at that same time as a verbal task then they were as good at the visual task as when performing it alone.
This shows that when undertaking two visual tasks they compete for the limited resources of the visuo-spatial sketch pad and provides strong evidence of its existence. It also provides evidence for the existence of 2 separate slave systems, one for visual tasks and one for verbal or auditory.
What is Neuroimaging evidence?
Brain imaging studies have also been very useful in showing the existence of individual components of working memory.
Paulescu et al (1993) used positron emission tomography (a PET scan) to record brain activity
participants were performing either verbal tasks (using the phonological loop) or visual tasks (using the visuo-spatial sketch pad)
They found that very different areas of the brain were active during each task.
They also found the phonological loop had subcomponents – ‘Broca’s Area’ was active in vocal rehearsal tasks and the ‘supramarginal gyrus’ was active when the phonological store was being used.
This showed quite clearly that verbal and visual tasks are performed by different brain regions and therefore suggests that the phonological loop and visuo-spatial sketch pad are physically separate from each other as the working memory model suggests.
The central executive has been investigated but is difficult to locate due to the nature of its role
What is case study evidence for WMM?
The KF Case Study supports the Working Memory Model.
KF suffered brain damage to his parietal lobe from a motorcycle accident that damaged his short-term memory
His long term memory was still intact.
Shallice and Warrington (1974) tested participants and found that KF had a 1 digit recall span
KF’s impairment was mainly for verbal information - his memory for visual information was largely unaffected
This supports the 2 slave systems in ‘working memory’ as his phonological store was affected not his visuo-spatial sketchpad
What is the effect of alzheimers on central executive?
Limitation of the model:
Difficult to investigate the coordination role of the central executive
Strengths:
Research has focused on clinical Alzheimer’s patients
Suggested that as the condition progresses, the function of the central executive decreases
Baddeley et al. (1991) conducted dual task experiments on young, elderly and Alzheimer’s patients using verbal and visual tasks simultaneously or separately. The performance of the Alzheimer’s group was no different to the other 2 conditions when completing visual or verbal tasks separately. However their performance was impaired when completing them simultaneously.
These findings seem to support the WMM as the role of the central executive is to coordinate the 2 slave systems. Therefore patients with Alzheimer’s find it difficult to do dual task simultaneously, which other people can do, due to the impaired central executive functioning.
What is phonological loop + Store and process?
Slave system, controls auditory info, Limited capacity (inner ear)
Phonological store- Holds words you hear, difficulty with acoustically similar words
Articulatory process- Used for seen and heard words (difficulty with long words). Silently repeats/loops words (Maintenance rehearsal).
What is neurophysiological evidence for WMM?
Williams syndrome
Normal language and impaired visual and spatial ability
Individual with this still have same phonological factors (word length and similarity) as others. Clinical evidence for visuospatial and phonological systems
Children with William’s syndrome struggled with predispositions (Over, under) suggesting association with visuospatial memory and language acquisition (Phillips et al 2004)
8 MARK ANSWER, DESCRIBE AND EVALUATE WMM
Working memory model was proposed by Baddeley and Hitch (1974), it had focused on Short-term memory or “working memory”, they felt that STM was composed of different stores (non-unitary).All STM info is kept here/retained and worked on for a short amount of time before being lost or transferred somewhere else.
The first store was the central executive which Controls two other slave systems and tasks they do(Phonological loop and visuo-spatial sketchpad)It focuses, divides, switches attention of slave systems and has a limited capacity, it is Modality free (Deals with info of all senses). Baddeley 1991 conducted a dual task experiment on young, old and Alzheimer’s patients using verbal and visual tasks singularly or simultaneously. Alzheimer’s group only impaired performance in simultaneous task, supports role of central executive and its control over slave systems, as Alzheimer’s patients struggled with dual tasks due to impaired central executive. The phonological loop(inner ear) is a slave system and controls auditory info, it has a limited capacity. It is made up of the Phonological store- Holds words you hear (such as verbal counting), difficulty with acoustically similar words and Articulatory process- Used for seen and heard words (difficulty with long words). Silently repeats/loops words (Maintenance rehearsal). Baddeley et al 1975 word-length effect experiment provides support for phonological loop. He had participants recall monosyllabic words and multisyllabic words, believed longer words would be harder to recall as they take longer to say and don’t accommodate for loop’s 20-30 second duration. Effect was proved. Baddeley had tested this with interference task and noticed that effect vanished as interference task prevented phonological loop remembering. The visuo-spatial sketchpad is known as the inner eye and is a slave system which deals with visual and spatial info where they’re temporarily store. It deals with imagery info or LTM info and is used in planning spatial tasks such as getting from point A to B.
Baddeley and Hitch (1976) Provides evidence for 2 separate slave systems for visual and verbal tasks by using a Dual task paradigm- Two tasks which utilise visuo-spatial sketchpad. When tasks were done separately, performance was better than performed simultaneously, undertaking two visual tasks causes competition for VS Sketchpad. The episodic buffer was proposed by Baddeley 2000, it holds visual and auditory info it is a more general store as other two are too specific, extra storage system but has limited capacity and it all integrates info from all areas including LTM. Working memory model is a very evidence based, credible model, such as case study of KF who had suffered parietal lobe damage due to accident, damaged STM, but had an intact LTM, Shallice and Warrington (1974) found that KF had one digit span. Impaired verbal memory, visual memory still intact. This case study supports the idea 2 slave systems as the Visuo-spatial sketchpad was unaffected and the phenological store was damaged. However, the WMM has been objected by….
