Biomarkers in Neurological Disease & Neurodegeneration
Eye movements can serve as valuable biomarkers for various neurological diseases due to the complex and far-ranging neural pathways and structures involved in their production and control. Many neurological conditions display abnormalities in eye movements, offering clinicians non-invasive and easily observable indicators for early diagnosis and monitoring, enabling timely intervention and potentially mitigating disease progression. Consequently, eye movements represent a promising avenue for the development of sensitive and accessible biomarkers that can significantly enhance the diagnosis, prognosis, and management of neurological disorders and injuries. My work in this area not only encompasses ocular motor biomarkers, but also extends to designing new eye tracking hardware and software.
Eye-hand coordination in health and disease
Coordination between sensory and motor systems is in many ways the foundation of functional limb and torso movement, because these synergies allow us to interact with the world. Beyond simple activation of the muscles, we must link or motor outputs to the information provided by sensory systems that tell us how and when to activate particular muscle groups to achieve functional goals. In the lab, we have begun to understand the character of eye-hand coordination deficits following stroke and its role in functional impairment, with the goal of developing novel rehabilitation strategies.
Saccade dynamics in health and disease
Planning, control, and coordination of eye movements are functions that recruit a surprising amount of neural real estate. This fact speaks not only to the intricacy and importance of eye movements, but also to the sensitivity of eye movements to damage or disease in a wide range of neural networks spanning the brainstem, cerebellum, basal ganglia and neocortex. We are interested in understanding the neural circuits responsible for ocular motor planning and control, both to advance basic neuroscience and to improve our understanding and detection of clinical syndromes involving these circuits.
Bayesian decision-theoretic models of motor planning
Every intentional movement of the limbs and torso represents a decision to move in a particular way and at a particular time. What speed is chosen? What trajectory and posture of the hand and finger are chosen as you reach for an object? Do you reach directly for the pencil on your desk and risk toppling your coffee cup, or do you plan a more circuitous trajectory that presents less risk of coffee disaster? We were the first to demonstrate a Bayesian decision-theoretic computation in human movement planning generally, in movement timing, and also in obstacle avoidance during reaching (i.e., the laboratory analog of the coffee cup scenario).
How do we orient ourselves to the world, and how do our own eye, head, and torso movements affect the way we perceive basic dimensions of space such as the direction of gravity, the orientation of our head and body relative to the upright world, and the spatial metrics of height and distance? These issues are important not only to daily life as we move within three-dimensional space, constrained by the Earth's gravitational field, but also for pilots and astronauts who must function within an altered gravito-intertial force background.
Novel methods of data analysis
Science advances through two routes: new theories and improved technical/analytical techniques. To continually improve and expand methods of data analysis in the behavioral and neural sciences, we develop novel methods of analyzing causal connections among perceptual discriminations, of identifying the coordinate systems used during human motor planning, and for the analysis and detection of eye movements.