Visual pointing and speed / accuracy trade-off in schizophrenia.

There is a challenge to understand schizophrenia cognitive deficits in terms of a common unifying hypothesis (i.e., context-processing deficit). We suggest that analysis of a low level of cognition, such as the natural tendency to adapt pointing movement time to the task difficulty, could provide the basis for understanding higher level processing, in the sense of context processing. In the present study, three-dimensional visually guided pointing movements were compared among patients with schizophrenia and healthy control subjects. Seventeen patients with schizophrenia and 13 controls, all right-handed, performed pointing movements on adversely sized targets displayed on a touch-screen. Results showed that, under this experimental procedure, the speed/accuracy trade-off was respected by the two groups, in that controls and patients achieved a constant level of precision whereas they increased reaction time and movement time when target size decreased. In addition, we provide a measurement of the pointing impact pressure, that is also affected by the target size in both groups. Our results suggest that schizophrenic patients did not exhibit a deficit in processing simple intrinsic context (target size) for the control of simple action. [ABSTRACT FROM AUTHOR]