We are normally not aware that our eyes and head are always in motion. Yet small, involuntary head and eye movements continually occur, even when we attempt to keep our gaze fixed on a point in the scene. It has long been known that the temporal modulations resulting from these movements are essential for seeing: the world becomes progressively fainter and will eventually fade altogether when the head and eyes are immobilized. However, the specific mechanisms by which fixational movements contribute to vision remain unknown. With funding from the National Science Foundation, Dr. Rucci and his team at Boston University will measure microscopic head and eye movements in human observers and reconstruct the input signals entering their eyes. The investigators will then use these data to quantify the impact of the observer's actions on the sensory flow of information and examine how this flow changes during the execution of different visual activities.
This research will investigate the mechanisms by which fixational movements contribute to the processing of visual information in the brain and the establishment of a stable visual percept. Elucidating the impact of fixational movements is critical to advancing our knowledge of how the visual system functions and how to build machines which replicate human visual capabilities. Furthermore, abnormal fixational eye movements occur in various pathological conditions. A thorough understanding of the functions of fixational eye movements may lead to treatment of the visual impairments associated with such conditions.