Abstract
Our eyes are continuously moving. Even when we attempt to fix our gaze, the position of our eyes is not stable. Furthermore, our eyes move every time we blink. No study to date has paid attention to the change in eye position caused by blinks and their interaction with other fixational eye movements (microsaccades and drifts).
We used eye movement data recorded during attempted fixation from seven awake rhesus macaques that were implanted with a scleral search coil in one eye. We found that the eye position at the end of a blink does not correspond with the position before its beginning (typical error of 0.8 degrees in macaques). Microsaccades were typically triggered in the 400 ms following a blink and their direction and magnitude matched the error of the blink better than chance. 61% of all microsaccades that occurred after a blink decreased the error. Large errors (> 0.2 deg) were more effectively corrected than smaller ones. Drifts also showed some level of correction but less than that of microsaccades. Our results show that blinks contribute to the instability of gaze during fixation and that microsaccades typically correct for the error introduced by blinks more than drifts. These findings provide critical new insights about eye position control during fixation.
Meeting abstract presented at VSS 2013