Abstract
The action potentials of normal extraocular muscles of a man were induced, and the discharge intervals of a single motor unit were observed during fixation of the gaze.
1. During fixation of the gaze on a point, the discharge frequency of a single unit is constant, but, if the gaze is moved to another point, it varies with the degree of contraction of the muscle in experiment.
2. When the average rate of discharge is over 30 per second, the variation of discharge interval is very small and the patterns of interval diagrams are uniform.
3. When the average rate of discharge falls below 30 per second, the variation of discharge interval increases and the patterns of diagrams give various types.
4. When the average rate of discharge is below about 10 per second, regularity of the discharge is scarcely found.
