Working Memory
From unthinkMedia
The term working memory refers to a brain system that provides temporary storage and manipulation of the information necessary for such complex cognitive tasks as language comprehension, learning, and reasoning. It is broken into three parts.
Contents |
Components
central executive
The central executive is an attentional-controlling system which:
- coordinate information from two or more slave systems.
- selects what to attend to
- supervises the cognitive process
This system is seen to be effected in patients with Alzheimer's. When using dual-task paradigm they show impairments when performing simultaneous multiple tasks, even when the difficulty of the individual tasks is adapted to their abilities.
visuospatial sketch pad
This is where temporarily store and manipulate visual, spacial and pattern recognition information.
- colors
- shapes
- speed of an object
- planning spacial movement
phonological loop
This deals with phonological and sound information
It consists of two parts: a short-term phonological store with auditory memory traces that are subject to rapid decay and an articulatory rehearsal component that can revive the memory traces.
- phonological store: short-term storage of speech or acoustic information that is subject to rapid decay (1-2 seconds).
- articulatory control process "inner speach" which facilitates subvocal repetition, and the ability to strengthen the memory traces. Visual information could be transformed into phonological information, by this same process.
This system is necessary for the acquisition of both native and second-language vocabulary.
Some other interesting concepts:
- acoustic similarity effect: Easier to remember words that don't share many similarities. This is due to less cues.
- irrelevant speech effect: This means that it is more difficult to process an image with a non meaningful auditory companion.
- word length effect: typically we could remember as many words as we could say in 2 seconds.
- articulatory suppression: Memory for verbal material is impaired when people are asked to say something irrelevant aloud. This is assumed to block the articulatory rehearsal process, thereby leaving memory traces in the phonological loop to decay
Limitations
- Millar indicates that working memory could only hold Seven, plus or minus two elements of information.
- Working memory could only process, manipulate, combine about 2-4 elements at a time.
- Peterson and Peterson (1959) state that without rehearsal, element could only be held in working memory for approx. 10 seconds.
Reference
Baddley, A., Working Memory, Science, New Series, Vol. 255, No. 5044 (Jan. 31, 1992), pp. 556-559
