bnormal Hemodynamics in Schizophrenia During an uditory Oddball Task

ackground: Schizophrenia is a heterogeneous disorder characterized by diffuse brain abnormalities that affect many facets of ognitive function. One replicated finding in schizophrenia is abnormalities in the neural systems associated with processing salient timuli in the context of oddball tasks. This deficit in the processing of salience stimuli might be related to abnormalities in orienting, ttention, and memory processes. ethods: Behavioral responses and functional magnetic resonance imaging data were collected while 18 patients with schizophrenia nd 18 matched healthy control subjects performed a three-stimulus auditory oddball task. esults: Target detection by healthy participants was associated with significant activation in all 38 regions of interest embracing istributed cortical and subcortical systems. Similar reproducibility was observed in healthy participants for processing novel stimuli. chizophrenia patients, relative to control subjects, showed diffuse cortical and subcortical hypofunctioning during target detection nd novelty processing, including bilateral frontal, temporal, and parietal cortices and amygdala, thalamus, and cerebellum. onclusions: These data replicate and extend imaging studies of target detection in schizophrenia and present new insights regarding ovelty processing in the disorder. The results are consistent with the hypothesis that schizophrenia is characterized by a widespread athologic process affecting many cerebral areas, including cortical, subcortical, and cerebellar circuits.