Brain Functions Underlying Visuospatial Attention Deficits in Schizophrenia

Objective: To test a neural circuit explanation for a visuospatial attention abnormality seen in schizophrenia. Specifically, the aim is to test whether broad monitoring deficits may be based on a disruption of the so-called sentinel function of the default network. Because the default network is modulated by nicotinic compounds, such finding would implicate a possible remediation strategy.\<TAB\> Study population: 24 people with schizophrenia, 24 matched healthy control subjects. Design: A group comparison of attention task performance and associated brain activity as measured by functional Magnetic Resonance Imaging. Outcome measures: Measures of attention task performance (reaction time, accuracy), BOLD signal within regions of the default network, degree of temporal association of BOLD signal with trial-by-trial reaction time.