Memory

Models of WM

There are two main types of WM models: those that focus on the way information is stored and those that focus on the processes involved in storing information. A very popular storage model is [Page 1148]the multicomponent model of WM by Alan Baddeley and his colleagues, in 2010. This model has four critical components: a phonological loop, a visuospatial sketchpad, an episodic buffer that interacts with information stored in LTM, and a central executive.

The phonological loop specializes in storing the serial order of verbal information. An example of a measure of the phonological loop is the nonword repetition test in which examinees must repeat multisyllable nonwords (e.g., megilobon) after hearing them. According to Baddeley’s multicomponent model, verbal information in the phonological loop will fade rapidly unless it is rehearsed. Rehearsal, or subvocally thinking about the sequential order of items over and over, helps recall because it keeps the memory traces in an active conscious state. Because of the phonological loop, people can remember words that sound different better than they can remember words that sound the same, and they can remember shorter words better than longer words. The storage capacity of the phonological loop has been shown to be important for vocabulary development in young children and for second language learning in adults.

The visuospatial sketchpad holds information about the sequential order of visual, spatial, and kinesthetic information. An example of a visuospatial memory task involves showing participants 5 × 5 grids of empty squares. A series of Xs appear in certain squares in the grid in a sequential order. Upon command, examinees are shown and empty grid. Then, they must point to the squares where the Xs appeared in the correct sequential order. For some memory tasks, these memory representations may be organized spatially; for other tasks, they may be organized visually or even motorically. The visuospatial sketchpad plays an important role in learning how to read and write.

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