We tested the range of visual fixation during head oscillations in a group of normal subjects who were asked to fix a visual target during oscillation of the head in the horizontal and vertical directions. Head and eye movements and the sum of both movements were recorded with a polygraph and stored in a microcomputer. To detect head and eye movements, we used a specially designed photodetector and an electronystagmographic method respectively. From the stored data, transfer function was calculated with head movements as input and eye movements as output. The normal range was defined as the mean and the standard deviation of the results.
Eleven healthy male and female adults were tested.
(1)The normal range obtained from polygraph records was 3.6Hz in the horizontal direction and 2.2 Hz in the vertical direction.
(2)The normal range obtained from transfer functions was 4-5Hz in both horizontal and vertical directions.
