Working Memory

Working memory is the brief, immediate memory for material that you are currently processing; a portion of working memory also coordinates your ongoing mental activities (Matlin, 2005, Ch. 4). One classic theory, the “Magical Number Seven," was developed by George Miller. Miller suggested that people can remember about seven items, give or take two. Miller used the term chunk to describe the basic unit in short-term memory. More recently, Nelson Cowan proposed that this number is actually closer to four. Click here to read more about Cowan’s theory.

Two sets of researchers, John Brown and Lloyd and Margaret Peterson, established that material held in memory for less than a minute is frequently forgotten. The Brown/Peterson & Peterson research technique involved quickly memorizing 3 letters, counting backgrounds, and then attempting to recall the letters. This early research underscored the fragile nature of memory stored for just a few seconds. The Brown/Peterson & Peterson technique inspired hudreds of studies on short-term memory and increased support for the cognitive approach (versus the behaviorist approach) (Matlin, 2005).

Another technique often used to examine short-term memory makes use of the serial position effect, which establishes that recall is better for items at the end of the list (recency effect) and at the beginning of the list (primacy effect). Therefore, the serial position of the stimuli plotted against probability of recall tends to form a U-shaped curve. However, a number of more recent studies that used visual–spatial stimuli (computer-constructed pattern of dots) have reported an absence of primacy effect and a limited recency effect (Broadbent & Broadbent, 1981; Frick, 1988; Hines, 1975; Phillips & Christie, 1977; Potter & Levy, 1969 referenced by Tremblay, Parmentier, Geraud, Nicholls, & Jones, 2006). To further test this observation, the Tremblay team tested whether the classical modality effect —- that is, the stronger recency effect for auditory items relative to visual items —- can be extended to the spatial domain. Computer simulations were done for visual-spatial (dot patterns), visual-verbal (letter patterns), and visual-auditory (letters spoken in a monotone male voice) tasls. The results demonstrated a modality effect —- greater recency in the auditory than in the visual modality -—in the recall of verbal items but not of spatial items. The results also suggested that the recency effect is stronger in the auditory modality than in the visual modality.

Working memory research led to the concept of proactive interference, which means that people have trouble learning new material because previously learned material keeps interfering with new learning. A recent study shows that older adults have the same mental acuity as younger people, but they have less room in working memory to handle additional information. Read the Developmental Psychology article by clicking here.

As researchers were contributing to the body of knowledge on working memory, there was still no comprehensive theory for this brief kind of memory – not until a cognitive psychologist, Alan Baddeley, developed his model of working memory.



Baddeley likened his model to a workbench where material is constantly being handled, combined, and transformed. The workbench holds both new material and old material that you have retrieved from storage, or long-term memory. A recent NASA study examines the “switch cost” in terms of time for the Central Executive to switch between cognitive tasks. Click here to read more.

Another study by Vladimir Sloutsky and Anna Fisher (Grabmeier, 2004) is interesting because the results run counter to the popular belief that people's working memory peak out at young adulthood. The researchers counter that very young children tend to similarity-based induction when examining pictures, whereas adults use category-based induction (or top-down processing using feature comparison model, or prototype approach). Click here to read more.

A healthy working memory is the ideal; however, for various reasons, many people have a deficit of working memory. Dr. Glenda Thorne discusses working memory deficits and how they can impact students. Students with working memory deficits may have problems following directions, solving math problems that have multiple steps. They may forget sentences they just read resulting in poor reading comprehension. Writing is arduous, as it involved the simultaneous retrieval of thoughts from long-term memory and organization of thoughts into grammatically correct sentences. Higher order thinking such as problem solving also suffers, since it involves holding components of the problem in mind while generating solutions. Click here to read the entire article.