Abstract
Ocular microtremors are known to be closely related to brain function and physiological states such as arousal, and measuring such microtremors may allow noninvasive brain function measurement. However, the differences between left and right eye microtremors have not been studied in detail. To analyze the differences between left and right eye movements, we developed a binocular microsaccade measurement system that simultaneously records the movements of both eyes at 800Hz. We used the system to examine five healthy male volunteers while performing a one-point fixation task for 30 seconds, and evaluated microsaccades using a formula that represents the difference between the left and right eye movements. As a result, we found several characteristics of the microsaccades. There was no left-right difference in the number of microsaccades, and the left-right difference in the time to reach peak velocity was less than 2.5ms. The results suggest that the difference in microsaccade direction at the time of peak velocity may indicate brain dysfunction and brain activities such as arousal. Additionally, the amplitude of the microsaccades may be regarded as a quantitative personal index of the subject.
