Information Processing and the Working Memory (WM)

At the core of information processing as it relates to the human learning system is the two-store memory model. While other ideas exist that attempt to explain the processes involved when individuals encounter new stimuli and how that information is encoded for future recall, I would like to take a look at the idea of working memory, its importance in human information processing, and its accepted makeup. Fenske states “the link between working-memory ability and general cognitive performance is so strong that many researchers seriously consider working-memory capacity to be the very root of fluid intelligence. (2011, p.1)

The idea of working memory dates back to the work of Miller who proposed that short-term memory or working memory can hold 7+ or -2 units of information. Around the same time, Akinson and Shiffrin (1968) developed their dual-store memory model which initially explained human information processing by breaking it up into three stages; sensory memory (SM), short-term memory (STM), and long-term memory (LTM). In an effort to more accurately define the actual processing that takes place within the human mind, Alan Baddeley and Graham Hitch (1974) focused their research on the limitations of the short-term memory stage. Baddeley explains “our own work has been focused on the information processing tasks rather than the [memory] system itself” (1998, p.86).

As a result of a change from the duration-restricting term, short-term memory (STM), working memory is termed so in an effort to better explain the process that takes place when new information is encountered and to “abandon the concept of a unitary store in favour of a multicomponent system” (Baddeley, 2000, p.417). Working memory is proposed to be limited in both the amount of information that it can process at a given time, around seven pieces or chunks of information, as well as in duration if not attended to, which is proposed to be around 20 seconds. Unlike short-term memory, working memory (WM) is thought to actively relate with the long-term memory. According to Baddeley, working memory is comprised of a central executive region which acts as a regulatory function for incoming information. It serves to decide what stimuli are recognized and attended to and those that are filtered out and discarded. The central executive initially was aided only by the “phonological loop” which stores acoustic and verbal information , and the “visuospatial sketchpad”, which stores visual information.

Most recently, however, Baddeley has added a new component to the makeup of working called the episodic buffer. Due to recent technologies in medical imaging and discoveries that document how multiple brain regions are active during the working memory phase of information processing, Baddeley concluded that the working memory is vastly more complex than his initial understanding. The episodic buffer “serves as a modeling space that is separate from LTM, but which forms an important stage in long-term episodic learning” (Baddeley, 2000 p.421). It also acts to integrate stimuli from a variety of places by incorporating the phonological loop and the visuospatial sketchbook.

References:

Baddeley, A & Hitch, G. (1998) Working Memory. Stirling, Scotland.

Baddeley, A. (2000) The episodic buffer: a new component of working memory. Trends in Cognitive Science. 4 (11): 417-423

Fenske, M.  (2011, May 5). The brain can juggle only so much. The Globe and Mail (Index-only),p. L.6.  Retrieved May 15, 2011, from CBCA Complete. (Document ID: 2337568241).