Abstract
In this study, 20 persons with cerebral palsy (10 of each sex, of whom 10 were athetosic and 10 spastic) and 20 normal persons (10 of each sex) were given simple and choice reaction tasks. In the simple reaction task, the subjects were asked to respond with elbow flexion or forearm supination to a light stimulus. In the choice reaction task, subjects were to respond with flexion to a light of one color (red or yellow), and with supination to a light of another color (yellow or red). Normal subjects' mean supination reaction time was significantly shorter than their flexion reaction time; the difference between the two reaction times on the choice task was significantly greater than on the simple task. For subjects with cerebral palsy, mean flexion reaction time was significantly shorter than supination time, and the difference between the two reaction times on the simple task was not significantly different from that on the choice task. Athetosic subjects' mean flexion reaction time was significantly shorter than their supination time, but the difference between their flexion and supination reaction times on the simple task was not significantly different from that on the choice task. For spastic subjects, mean flexion reaction time was shorter than supination reaction time on the simple task, but, on the choice task, mean reaction time for supination was slightly shorter than for flexion. "Flexion error reactions" were more frequent than "supination error reactions" in the subjects with cerebral palsy. These results suggest that persons with cerebral palsy are different from normal persons in the processing mechanism of the motor output stage. They also suggest that the relation of the jedgment stage to the motor output stage would not be serial and independent in persons with cerebral palsy.
