Binocular coordination in microsaccades

When viewing a stationary object, our eyes perform miniature eye movements, which are classified as drift; tremor and microsaccades. While drift and tremor are irregular movements with a low correlation between the eyes, microsaccades are ballistic movements, traditionally defined as binocular phenomena. Here we propose that microsaccades can be both binocular and monocular with different statistical properties, in particular with different mean orientations. For this analysis, we have developed a new algorithm for the detection of microsaccades based on a transformation to 2D velocity space. Based on our algorithm, we investigate oculomotor responses to display changes. We show that the rate of binocular microsaccades is strongly modulated by changes in visual input. These results suggest that the occurrence of microsaccades is a dynamically rich phenomenon, which may give new insights into the specific functional relevance of microsaccades and may be used to study binocular aspects of oculomotor control.