Tue11Apr20176:00 pmLusa Bakery and Cafe, 1120-1122 North Lamar Blvd Oxford, Mississippi
Oxford Science Cafe
Dr. Susana Martinez-Conde,
Laboratory of Integrative Neuroscience,
State University of New York — Downstate Medical Center
Vision is All About Change
Your eyes are the sharks of the human body: they never stop moving. In the past minute alone, your eyes made as many as 240 quick movements called “saccades” (French for “jolts”). A portion of our eye movements we do consciously, and are at least aware of on some level. But most of these tiny back-and-forths and ups-and-downs are unconscious and nearly imperceptible; someone staring directly at your eyes would miss most of them. Scientists long believed that we use two types of oculomotor behavior to sample the visual world, alternating between big saccades to scan our surroundings and tiny ones to fix our gaze on a location of interest. Explore, fixate, repeat, all day, every day. It seemed to make intuitive sense that we would have one brain system for exploring the environment and another for focusing on specific objects. But it turns out that exploration and gaze-fixation are not all that different processes in the brain. Instead, our eyes scan visual scenes with a same general strategy, whether the images are huge or tiny, or even when we try to fix our gaze. This insight may offer clues to understanding normal oculomotor function in the healthy brain, and oculomotor dysfunction in neurological disease.