He specializes in working memory, the small amount of information held in mind and used for language processing and various kinds of problem solving.
[1] For example, the work on amnesia indicates that individuals who usually cannot form new memories because of stroke or brain damage often demonstrate considerable ability to do so when the information to be memorized is surrounded by several minutes with minimal visual or acoustic interference.
[22] Cowan's theoretical model[3][10] addresses key puzzles in information processing using a new approach in which there are two aspects of working memory: the activated portion of long-term memory, which includes rapidly-learned information limited only by decay and interference among similar features and, within this activated portion, a focus of attention limited to about 3-4 separate items or chunks in typical adults.
[29] They also used the improved methodology to replicate the early, poorly-studied finding that about a third of participants notice their names unexpectedly presented in a channel to be ignored .
[11] These factors that could not completely account for working memory capacity growth include the allocation of attention to relevant items,[34][35] encoding speed and rehearsal,[36][37] and knowledge.
[39] Recent evidence suggests that older children become better able to notice patterns in the stimuli that allow them quickly to memorize information and thereby ease the load on the focus of attention.
Consequently, older participants can remember tones or words and colors at the same time, better than younger children with less interference between the two modalities[40] Similar findings have been obtained in the area of adult aging,[41] with a U-shaped development across the life span in the number of items that can be held in working memory without mnemonic strategies.
Cowan's first experimental project, in a high school research class, involved supercooling suspended animation of rotifers, with guidance from his instructor and Commander Perry at the Bethesda Naval Hospital.
Cowan's home was within biking distance along Rock Creek Park to the National Institutes of Health in Bethesda, MD, and in the summers when home from college, he volunteered there one year (with Monte Buchsbaum), learning computer programming and studying hemispheric laterality, and had a paid assistantship the next summer (with David Jacobowitz).
The latter led to his first publication on a study that he suggested to the scientists, on examining the synergic and antagonistic actions of two neurotransmitter systems in rats.