Functional Neuroimaging and the Prefrontal Cortex: Organization by Stimulus Domain?

Abstract

Working memory is the set of cognitive operations that maintains and processes information “on-line”. It has been characterized both as a mental workspace (Baddeley, 1986) and as a set of operations that allow the efficient allocation of cognitive resources (Carpenter et al., 1990, 1999). Working memory typically is thought to be of limited capacity, between 4–7 items (Miller, 1956; Cowan, 2000), of limited duration, on the order of seconds (Peterson and Peterson, 1959) and as involving a number of separable sub-mechanisms, among these, rehearsal processes, domain-specific storage buffers, and a set of executive processes that are thought to operate on currently active information (Baddeley, 1986; Smith et al., 1996). This chapter focuses on the cognitive operations mediated by the frontal lobes in the service of working memory tasks.KeywordsPrefrontal cortexspatial memoryobject learningverbal memoryworking memoryfrontal lobeshuman memoryfunctional MRIpositron emission tomography