The study is has a so-called double blind, randomized - yet balanced - cross-over design, in which 24 male patients with schizophrenia are included. After inclusion in the study, patients will be assessed in a test-battery, in which psychophysiological parameters of their basic information capabilities are quantified. Following this, the patients will be treated with either risperidone or sertindole for a period of 10 weeks, after which they will cross-over to the other treatment (the order of treatments is randomized (and balanced)). The battery of tests is repeated after the first and second treatment period. In addition, a second test-battery will be performed at these follow-up intervals, to assess neuropsychological parameters of information processing. To evaluate the extend of the treatment effects, the patients will be matched (age, gender, parental socioeconomic status) to 24 healthy controls.