Visual Effects on Finger Tremor in Normal Subjects and Anxious Patients

Abstract

Sutton and Sykes (1956) studied the characteristics of the tremor superimposed on a voluntary muscular contraction under two conditions; (a) when the subjects were provided with a visual display of the accuracy with which they were maintaining a constant force, and (b) when they carried out the same task with the eyes closed. It was observed that when the subjects' eyes were closed, the tremor amplitude at 8–9 c/s (cycles per second) was sometimes relatively much diminished. In some subjects there was evidence of a smaller reduction in amplitude at other frequencies. Young (1933) had made similar findings using a less satisfactory technique. The findings of these workers have been confirmed and extended in another investigation (Carrie, 1965).