Differential contribution of the prefrontal cortex versus other cortical/subcortical areas in implementing executive control

Mark D’Esposito
UC Berkeley
Department of Neurobiology
Berkeley, CA

Abstract

To this day, the frontal lobes remain a region of human cortex for which it s function continues to elude neuroscientists. Evidence from neuropsychological, electrophysiological and functional neuroimaging supports the notion that the prefrontal cortex (PFC) is necessary for temporarily maintaining relevant information in an active state, a process that is critical for the voluntary control of behavior. The extensive reciprocal connections from PFC to virtually all cortical and subcortical structures places it in a unique anatomical position to monitor and manipulate diverse cognitive processes. However, little is known about the differential contribution of PFC versus other cortical/subcortical areas in implementing executive control. In this talk, I will present evidence from several event-related fMRI studies that support a model of executive control in which PFC biases activity in posterior stimulus-specific association cortex in favor of behaviorally relevant information. Moreover, the temporal dynamics of the signal from the PFC vs. posterior stimulus-specific association cortex is consistent with perceptually-driven bottom-up flow of information when encoding representations that must be maintained, and internally-driven top-down flow of information when decisions and actions are made based on maintained representations. Hopefully, an improved understanding of the physiological basis of executive control derived from powerful techniques such as fMRI and ERP will lead to a narrower and more useful view of frontal lobe function

Return to the Symposium 2003 Main Page