ABSTRACT
OBJECTIVES: This study investigated the compensatory neural correlate of selective attention deficit in schizophrenics showing near-normal performance. METHODS : A 'modified Stroop' was developed that can be used measure the response time during functional imaging. An event-related functional magnetic resonance imaging study was carried out in 10 clinically stabilized schizophrenics and 10 healthy controls during the performance of a 'modified Stroop'. In the 'modified Stroop', the subjects were required to respond with a two-button mouse to whether or not the color of a subsequent word corresponded to one of T-shirt. The significantly activated brain regions were investigated in a voxel-wise t-test of the Stroop load. RESULTS : Schizophrenics, compared with healthy controls, showed poorer response time, but had similar accuracy. Compensatory activation in the right inferior frontal gyrus (IFG) was observed in schizophrenics. The left paracingulate sulcus was less activated in the schizophrenics than in the healthy controls. CONCLUSION : These results suggest that, in schizophrenics showing a normal accuracy during the Stroop, selective attention deficits might be related to the left paracingulate sulcus as well as the anterior cingulate. In addition, their deficits may be compensated with the right IFG.