Neuropsychology of vision and eye movements

Nearly half of the human brain is involved in processing vision and eye movements. These functions can be impaired by strokes or brain tumours, as well as neurological disorders such as schizophrenia and autism. Using imaging technologies, experimental vision tests and eye movement recordings, Dr. Jason Barton is studying how neurological diseases disrupt the brain_s sensory and motor processing systems. Recognizing faces is one of the most demanding tasks for our visual systems, requiring both high-level perception and memory. Faces differ in only subtle ways in structure and shape, and the average person sees hundreds of faces in a day: despite this, humans are able to recognize faces effortlessly. Dr. Barton is studying how face perception is organized in the normal human brain, and how it is disrupted in patients with brain damage from strokes and surgery, and in those with Asperger_s disorder, an autism-like condition. Dr. Barton is also investigating saccades, rapid eye movements that shift our gaze toward a target and antisaccades, an unusual eye movement in which subjects look away from a suddenly appearing target. Performance on novel tasks like antisaccades can tell us something about how we exercise control over our responses to the environment. Abnormalities on such tasks can inform us about the problems with response control in conditions like schizophrenia. These studies will improve our understanding of these neurological disorders, how they disrupt visual processing, and lead to the development of future remedies.