UC San Diego

Vision and movement are instrumental components of normal functioning in everyday life. Due to this importance, it is valuable to understand the neurological mechanisms which underlie these processes and how they are employed. Correspondingly, much research is done on deficits in these processes and how people are impacted by such deficits. This dissertation focuses on the development of techniques to better be able to perform investigations into vision, movement, and the interaction between them. In order to study vision it is often important to know where the eyes are looking and how they are moving; this is often done using a method of eye tracking, typically using a camera. As part of this work, eye tracking based upon electroocculography (EOG) was developed as a potentially inexpensive, high temporal resolution eye tracker system, with capabilities of tracking gaze fixation in 3D space. An experimental calibration setup and procedure were created to calibrate and test the capacities of the EOG based eye tracker, including comparison to a standard, camera based eye tracker. Vision is also involved in movement through space. Navigation within an environment requires the utilization of cues, typically visual ones, to determine location, plan a path, and subsequently execute it. In this project a virtual reality system and experimental platform, the Virtual Environment Human Navigation Task (VE-HuNT), was created to assess the navigation skills and strategies utilized within conditions applicable to everyday life. VE-HuNT was employed to investigate the effects of visual impairment due to glaucoma on navigation, and the aspects of the environment that would improve functioning in these individuals. Behavioral metrics for wayfinding ability were assessed and the impact of glaucoma on the ability of subjects to utilize environmental cues for wayfinding was determined. Together the outcomes of these two complementary projects further the ability to perform human cognitive research under conditions representative of typical human activity. As an important tangible benefit of these advances, the improved capabilities for assessment of clinical conditions which impact such activities open up new avenues for neurological understanding of vision and movement.