Effects of atypical neuroleptics on alertness and visual orienting in stabilized schizophrenic patients: a preliminary study.

It has been shown that schizophrenic patients treated with conventional neuroleptics display a general slowness in latency in simple reaction-time tasks and a disengagement deficit in visual-orienting tasks. Yet, the influence of atypical neuroleptics on attention is still controversial. The purpose of our study was to investigate the effect of atypical neuroleptics in tasks requiring alertness, selective attention or visual orienting. Thirteen stabilized schizophrenic patients receiving atypical neuroleptics were compared to 13 healthy controls matched for age, gender, and study level, in a choice reaction time (CRT) task and a visual-orienting task cued target detection (CTD) task. The results showed that patients and controls obtained comparable reaction times (RTs) in the CRT task. In the CTD task, both groups had comparable RTs but the presence of invalid cues caused a greater attentional cost in both visual fields for patients compared to controls, indicating a symmetrical disengagement deficit. To conclude, patients treated with atypical neuroleptics had a phasic alertness ability similar to controls. By contrast, an impairment of disengagement was present in those patients. Thus, atypical neuroleptics could have a positive influence on certain but not all attentional domains.