Reduced Processing Resource Availability in Schizotypal Personality Disorder: Evidence From a Dual-Task CPT Study

Performance on a dual-task information processing task was investigated in 23 schizotypal personality disorder patients (SPD), 29 patients with other noncluster A personality disorders (ORD) and 8 nonpsychiatric healthy controls (NC). All participants were assessed using a computer-based visual continuous performance test (CPT) and an auditory CPT individually, and administered again simultaneously in a dual-task condition. The SPD group showed a greater increase in the number of errors of omission than the OPD group or normal controls on the CPT tasks in the dual-task conditions. Performance operating characteristics indicated that the SPD patients did not allocate their attention in a manner different from the healthy controls, suggesting that poorer performance was due to resource limitations in the dual task condition and not strategic failures. These results are similar to previous studies of patients with schizophrenia, where performance deficits on information processing tests have been shown to be related to resource limitations more than failures in effective allocation of attention.