This research proposal aims to use functional magnetic resonance imaging and neurocognitive assessment batteries to examine the role of prefrontal cortex in the inhibition of distracting stimuli during working memory (WM) performance, and impairments of these functions in schizophrenia. The prefrontal cortex has been proposed to serve as a protective mechanism for memories by inhibiting irrelevant stimuli, but the relationship between individual ability to inhibit and prefrontal maintenance patterns during relatively greater or less distraction has not been addressed. This study will examine the effects of varying levels of distraction on prefrontal activation during a spatial working memory task. The information acquired from the neuroimaging study will further be combined with behavioral neurocognitive testing measures of inhibitory control to assess the role of individual differences in inhibitory ability, and the relation of these abilities to patterns of prefrontal activation and interaction with posterior brain areas. Study 1 will examine this relationship in healthy controls, while study 2 will focus on individuals with schizophrenia, a population with well documented deficits in working memory, inhibition and prefrontal function. ? ?
