working memory Flashcards
Define working memory
Working memory is a cognitive system that refers to the process that temporarily stores and manipulates information, so that we can use that information to undergo complex cognitive tasks (e.g. follow a conversation).
What are the components of the WM model?
The latest model has four main components. These are: a modality-free central executive, a phonological loop , a visuospatial sketchpad and an episodic buffer. Each of these components have limited capacities.
Define the phonological loop.
The phonological loop is the component of the working memory in which speech based information is stored and subvocal articulation occurs.
Describe the brain areas associated with the PL
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phon store = left inferior parietal cortex
- Some brain-damaged individual have very poor memory for auditory-verbal material but essentially normal speech production- indicating they have damaged phonological store but an intact articulatory control process. Patients typically have damage to the left-inferior parietal cortex (Vallar & Papagno 1995.)
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artic loop =left-inferior frontal cortex
- other brain damaged patients have an intact phonological store but a damaged articulatory control process shown by a lack of evidence for rehearsal. (left-inferior frontal cortex (vallar & Papagno 1995)
define the visuo spacial sketch pad.
Component of the WM that deals with visual and spatial information
describe the brain areas associated with the VSSP
Brain areas associated with the two components of visual-spatial sketchpad
Zimmer (2008) found areas within the occipital and temporal lobes were activated during visual processing. In contrast areas within the parietal cortex were activated during spatial processing.
describe the Central executive.
This is responsible for monitoring and coordinating the operation of the slave systems (the phonological loop and the visa-spacial sketchpad) and long term memory. The central executive decides what information is attended to and gives priority to certain activities but does not store information per se.
describe the process of the CE
Evidence from behavioural studies (miyake et al, 2000) and neuroimaging studies (Glascher et al, 2012), suggests that the central executive consists of various related but separable executive processes. These include functions of inhibition, shifting and updating (as proposed miyaje, 2000 in her unitary/diversity framework).
what is the episodic buffer?
This is a limited capacity subsystem of the working memory that stores multimodal information (from the phonological loop and the visuo-spacial sketchpad) and serves as an interface between LTM and WM.
How is WM measured?
- Working memory capacity can provide an insight into how much information a person is able to process at the same time and is measured by assessing storage and concurrent processing. For example, Daneman and Carpenters (1980) span test requires participants to read a list of sentences. The participants are required to process them in terms of meaning (the processing load ) and are required to recall the last words in the sentence ( storage)
- Weschler memory scale tests (WMS- III uk) used to assess WM function= digit span, spatial span & letter-number sequencing
How is the PL measured?
- digital-span tasks (the amount of digits you can hold consciously in one moment)
- nonword repetition tasks, such as Gathercoles non-word reputation task( participant asked to repeat a stream of increasingly long words).
How is the VSSP measured?
- Matrix Span (where participants view a grid of black and white squares and then later are asked to recall the position of all the black squares)
- Corsi block test (where the experiment taps a sequence of blocks from an array of nine blocks and the asks the participant to recollect the items) are examples of this .
How is the CE measured?
- Measurements of executive function are less clear cut and there is some dispute over the best ways to measure executive function.
- In clinical settings, the most widely used measures are the Wisconsin card sorting tests and verbal fluency.
- The Wisconsin card sorting test is a neuropsychological test of “set-shifting”, i.e. the ability to display flexibility in the face of changing schedules of reinforcement.
- Verbal fluency measures how quickly people can retrieve category specific information from LTM.
- One of the widely used measures of CE performance in research is the random generation task. This requires subjects to generate a list of items such as digits or letters in a random order without referring to stereotyped response sequences.
What role does the phonological loop have in communication?
- Examining language for logic - Baddeley and lewis (1981) found that articulatory suppression interfered with a subjects ability to detect errors of logic or word order in a sentence, suggesting that the function of the phonological loop may be to hold on to the sentence for long enough to analyse it for logic, word order and overall meaning.
- Learning language - Other studies have suggested that poor WM span affects language, not in terms of comprehension, but in terms of how we learn language.
What role does the visuo-spacial sketch pad have in communication?
- Supports verbal learning via imagery mnemonics
- It also supports our grammatical comprehension for words of spacial position (e.g. above, below, besides). This was found to be an impairment in people with Williams Syndrome ( a condition that affects the VSSP but not the PL).