Experimental Studies On Optokinetic Nystagmus II. Normal Humans

Abstract

This study is an assessment of the functioning of the oculomotor neural reflex in humans. Optokinetic stimuli have been applied by rotating a large drum with white stripes on the wall at different velocities around the subjects and the nystagmic movements were recorded electronystag-mographically. In the first group of 18 subjects the responses varied both in frequency and amplitude. However, there seemed to be two general patterns. One pattern showed a tendency toward small amplitude and high frequency nystagmus and the second pattern small frequency and large amplitude nystagmus. In the second group of 32 subjects two tests were made. During the first test the subjects were instructed to follow the stripes, and in the second to stare straight ahead. By following the specific instructions, two different sets of optokinetic nystagmus responses were obtained that corresponded to the two patterns observed in the Group I experiments. Whether “stare” or “look” the responses of the individuals showed a similarity to each other as indicated by the quantitative measurements of the different parameters of the nystagmus. Analysis of the responses showed that the tests have physiological constancy and may be of experimental and clinical value.