In patients with schizophrenia, early as well as late stages of information processing can be deficient. Therefore, it is important to determine the earliest occurrences of aberrant processing since deficits on these stages may cause abnormal processing on later, e. g. cognitive, levels. In order to investigate this issue in the visual domain, we studied one of the most basic feature integration mechanisms, namely feature fusion. Our results indicate that in schizophrenic patients this integration mechanism is qualitatively intact but reveals quantitative impairments that may influence later processing stages.