Attentional asymmetry in schizophrenia: the role of illness subtype and symptomatology.

1. Patients with undifferentiated and paranoid schizophrenia, and normal controls were compared using 2 versions of the covert orienting of attention procedure which evaluate exogenous (automatic) and endogenous (controlled) cuing mechanisms. 2. For both tasks, attentional performance varied with illness subtype, but in different ways. 3. On measures of automatic orienting undifferentiated patients showed evidence consistent with a mild right visual field deficit, while paranoid showed a reduction of inhibition-of-return, a mechanism which biases against returning to previously attended locations. 4. On measures of controlled orienting only the undifferentiated group showed the asymmetry of costs which has been the emphasis of most previous studies. The pattern of cost asymmetry was similar to that previously associated with prominent negative symptoms. Additionally, the magnitude of cost asymmetry correlated positively with negative symptoms in the overall patient group. 5. These findings show that systematically considering cue type and symptomatology are critical in interpreting varying patterns of performance by different groups of patients with schizophrenia on the covert orienting procedure. The implications of these findings for understanding the psychopathology of attention in schizophrenia and its neurobiological substrates are discussed.