A topic in Learners’ conceptions and thinking
Memory is a key concept related to learning – but some common-sense ideas about memory are found to be questionable at best.
Working memory (WM)
Working memory is the name given to a component of the cognitive system. Despite being called a 'memory' WM is not somewhere where information is represented for long periods of time, but is considered to be associated with conscious thinking , so information (from the senses, or from long-term memory) only remains in WM whilst it is being consciously mentipulated.
"Whereas LTM has effectively infinite capacity, and representations in LTM are retained, if subject to modification, indefinitely, WM has a very limited capacity and is much more transient – being about what is currently the focus of attention: ‘working memory refers to the temporary retention of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment’ (D’Esposito, 2007, p. 7).
…WM is considered to be a transient type of memory, concerned with what can be ‘held in mind’ rather than what is represented permanently in neural circuits – although it draws upon information represented in that way."
Taber, 2013, pp.105-106
WM components
The WM is considered to have several components, as well as 'the central executive' which manages its functions, including facility for keeping imagery in mind, and a short burst of sound (imagine yourself repeating an unfamiliar telephone number in your head)
"To support the executive functions of WM, it appears to have its own system of buffers that allow certain types of information to be held available for processing.…
The Visuo-spatial Sketchpad: The visuo-spatial sketchpad allows the person to hold in mind, and manipulate, imagistic representations. This supports a form of nonverbal intelligence. Baddeley (2003) notes its importance in engineering and architecture and gives the example of the type of thought processes that Einstein reported as crucial to his theorising.
The Phonological Loop: The phonological loop acts as store, which holds memory traces from a short period: a matter of a few seconds. However, it is supported by an ‘an articulatory rehearsal process that is analogous to subvocal speech’ (2003, p. 830). In effect the data in the store is ‘played’, and the output fed back into the store to refresh it. This store allows us to rehearse small amounts of information, such as a telephone number we have just heard.
The Episodic Buffer… is seen as a ‘modelling space’, but one that is able to handle different types of information…"
Taber, 2013, p.106
WM Capacity
One of the key features of working memory, and one of special interest in terms of learning, is its limited capacity.
"WM is considered to be subject to severe restrictions on its capacity to process information, as if it has a very limited number of ‘slots’ for data. Although there is variation between individuals, and some apparent expansion early in life which may reflect access issues rather than actual capacity, a common value that is quoted as typical is 7±2: that is, that most people can ‘keep in mind’ from 5 to 9 distinct quanta of information at a time. This number derives from pioneering work by Miller (1968). Memory ‘span’ is commonly determined by tasks such as the ‘digit span technique’, which explores the length of a string of random digits that can be reliably reported back in the correct sequence, immediately after a (verbal or visual) presentation, before the subject begins to make mistakes. The largest length of string that a person can reliably report is their digit span. It has been found that for ‘normal’ adults (those without some kind of mental deficit/impairment), this is usually in the range ‘seven, plus or minus two’ (Parkin, 1993).
More recent research (Cowan, Chen, & Rouder, 2004; Mathy & Feldman, 2012), whilst supporting Miller’s general principle, suggests that Miller’s magic number may actually overestimate the number of available ‘slots’ in working memory, because of our natural tendency to spot patterns that allow us to ‘chunk’ information."Taber, 2013, p.108
(Read about 'Chunking and learning')
Work cited:
- Taber, K. S. (2013). Modelling Learners and Learning in Science Education: Developing representations of concepts, conceptual structure and conceptual change to inform teaching and research. Dordrecht: Springer.
