Grant: Master's Award: Canada Graduate Scholarships

While sitting alone in a quiet room, you suddenly feel something touch your leg. Under many circumstances this could result in fear or surprise, and you may automatically kick at the offending source. However, if you happen to own a cat, it may be wise to repress this response. Determining the appropriate action for a particular situation is a vital aspect of human behaviour. This ability to respond flexibly to environmental cues, and the facilitation or suppression of many automatic responses depending on the situation, is the hallmark of executive control. In the laboratory, this behavioural flexibility can be studied by training subjects to do environmentally dependent tasks with the same underlying action, and recording brain activity while these tasks are performed. A saccade is the fast movement of an eye, head, or other animal body part. The saccadic eye movement system is an excellent model for environmentally dependent tasks, because it is easy to measure, and there is considerable knowledge of the underlying neural circuitry which participates in controlling gaze. In some cognitive disorders, such as Parkinson's, Huntington's, and Attention Deficit Hyperactivity Disorder, saccadic eye movements have distinct deficits. Since recording eye movements is fast and inexpensive, the saccadic eye movement system may represent an early detection system for these disorders. Deficits in saccadic eye movements may also implicate corresponding changes in behavioural flexibility. It is therefore important to fully understand how saccadic movement is controlled, as these areas may be altered in some disorders. By training monkeys to perform saccadic eye movements, this study aims to record interactions between specific areas of the brain, in order to better understand the underlying changes in these disorders.