Assessing Higher Order Functions of the Cerebral Cortex Using Functional MRI: The Working Memory Function of Prefrontal Cortex as a Case Study

The prefrontal cortex has been implicated in a variety of higher cognitive faculties, including planning, problem solving, and language. However, little is known about the specific cognitive mechanisms that this brain area subserves. The application of functional neuroimaging techniques has recently begun to shed light on this question. This chapter briefly reviews the role of frontal cortex in working memory, and discusses a recent study designed to examine this function of prefrontal cortex using magnetic resonance imaging. The results of this study support the role of prefrontal cortex in working memory, identify specific regions that appear to be involved and, more generally, demonstrate that functional MRI (fMRI) using conventional scanning equipment can be used to study the activation of associative cortex in individual human subjects. These results set the stage for more detailed examinations of the functional organization of prefrontal cortex, as well as other regions of associative cortex.