Eye-tracking patterns in schizophrenia. An analysis based on the incidence of saccades.

Saccades occurring when tracking a sine-wave target and when fixating a stationary target were studied in the following three groups: schizophrenics, other psychiatric inpatients, and normal controls. The frequency of saccades when tracking and when fixating was significantly greater among schizophrenics than among the two comparison groups. The pattern of occurrence of saccades within cycles of the sine movement was similar in the three groups; the greatest occurrence was at the highest target velocity and the lowest occurrence was at reversal points. The data are interpreted as consistent with the hypothesis of a failure on inhibiting mechanisms.