Visuomotor tracking performance in schizophrenia: relationship with psychopathological subtyping

30 schizophrenic outpatients (RDC) under neuroleptic maintenance treatment completed a visuomotor tracking task with four degrees of difficulty. The mean efficiency of performance was measured in bit per second from the difference between the target signal and the tracking signal. Clinical assessment was accomplished with the BPRS, CGI, and GAS. Besides generally poorer tracking performance in schizophrenics compared with healthy volunteers the main finding was a relationship between tracking performance and psychopathological subtyping. Negative symptoms were related to a generally lowered task performance, irrespective of task difficulty. However, this effect disappeared by controlling for illness duration. On the other hand, there was a syndrome-specific interaction effect with task difficulty: Schizophrenics with positive symptoms performed poorly, especially in the most difficult task condition. Generally, there was no significant relationship between daily neuroleptic dose and tracking performance. Results are discussed with respect to a differential deficit in attention in schizophrenic subgroups.