This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
People are often surprised to learn that their eyes never stop moving, even when they fixate their gaze. Even more surprising: if our eyes did stop moving, we would become blind to stationary objects due to a brain process called "neural adaptation". Since we fixate our gaze about 80% of the time, fixational eye movements are responsible for driving most of our visual experience of stationary objects. The physiology and perception of fixational eye movements are therefore critical to understanding the neural mechanisms that overcome neural adaptation and maintain visual awareness. A type of fixational eye movement, called microsaccades, produces bursts of neural activity in visual system neurons and counteracts adaptation and visual fading. However, no study to date has determined the role of microsaccadic dynamics (rate, velocity, and magnitude) on high-level visual processes, from either a perceptual or a physiological viewpoint. With support from the National Science Foundation, Dr. Susana Martinez-Conde and colleagues at the Barrow Neurological Institute will address this gap in knowledge by determining the relationship between microsaccadic dynamics and a variety of high-level viewing tasks. The project will measure microsaccade dynamics during viewing tasks with varying attentional/cognitive demands and will also examine the neural activity that occurs in correlation to microsaccades during such viewing conditions.
Because much, if not most, of our visual experience occurs during fixation, understanding the role of fixational eye movements in perception and cognition is of utmost importance. This research will determine how viewing conditions differentially modify the dynamics of microsaccades, as well as their impact on neural activity and successful task completion. The funding from this application will be used to support a new research group at the Barrow Neurological Institute which can provide research training opportunities for undergraduate, graduate and post-doctoral trainees in neuroscience. It will broadly disseminate results through publications to scientific as well as lay audiences, thus enhancing scientific understanding by the public.
