Schizophrenics' reflexive saccades are found unimpaired in most studies, but abnormal saccadic distractibility can be shown in the antisaccade task, when a saccade should be directed away from a peripheral stimulus to its mirror image location. This could indicate problems with suppressing reflexive saccades to peripheral stimuli and/or deficiencies in the initiation of voluntary saccades without a physical target.

In this study, saccadic eye movement parameters and their interrelationship were investigated under different experimental conditions. 23 healthy controls and 34 schizophrenic patients were studied with various eye movement tasks (reflexive refixation task with and without temporal gap, voluntary saccades after central arrow cue, antisaccade task).

Schizophrenics showed normal latencies in the gap- and overlap-paradigm, indicating that no generalised deficit was present in schizophrenics. Number of express saccades in the gap paradigm was equal in both groups. Saccades after the central arrow and antisaccades were generally slower than reflexive saccades in the prosaccade task. In schizophrenics, these voluntary saccades were delayed to a similar degree during both the antisaccade and the arrow cue condition in schizophrenics relative to controls. Furthermore, patients made significantly more errors in the antisaccade task. Correlation between antisaccade latency and latency of arrow-cued saccades was -0.61 showing close relationship between these tasks.

Results support the hypothesis that initiation of voluntary saccades rather than inhibition of unwanted reflexive saccades is the process sensitive to schizophrenic pathology.