Visuo-motor reaction times of normal subjects and schizophrenics using inverting prisms

The visuo-motor reaction times of normal subjects and schizophrenics were measured to investigate adaptation of eye-hand coordination in schizophrenics under modified vision. Reaction time was measured in 32 normal subjects and 32 schizophrenics by using a rectangular board with 24 illuminated buttons. Subjects' task was to press an illuminated button as quickly as possible under normal and modified vision. Time elapsed from when the light was switched on to when the button was pressed was measured as the visuo-motor reaction time in msec. Three conditions were set up: control in normal vision; inverted using an inverting goggle; reversed using a reversing goggle. In general the visuo-motor reaction times of schizophrenics were slower than those of normal subjects. But in the reversed condition, there was no significant difference between normal subjects and schizophrenics. The visuo-motor reaction times of schizophrenics in the reversed condition showed a large dispersion with the fastest being faster than that of any normal subjects. It is suggested that there may be a group among schizophrenics whose basic paradigm of visuo-motor association is different from that of normal subjects.