Stare at the black point in the center of the image for a few minutes. Then divert your attention to the white point (left). You will notice that in the pattern between the squares there are "ghost" dots moving from one side to the other. Why? Although you may not notice it, when we try to fix our eyes, our eyes do not stay still, but move rapidly from back to front, in almost imperceptible microscopic movements known as microsaccades .
Researchers at the Salk Institute for Biological Studies in La Jolla (United States) have just identified the brain region that controls these rapid involuntary movements of human eyes. The scientists, who publish their work in the journal Science , conclude that the brain region that controls these extremely fast unconscious movements is the same that participates in voluntary eye movements, that is, the rostral superior colliculus. This structure also participates in voluntary movements of the eyes, suggesting that microsaccades could serve an important role in maintaining attention and visual perception , and not just "noise" from the ocular motor system.
