Publication Summary and Abstract
Chambers, J. M., Gurney, K., Humphries, M. & Prescott, T. (2005), Mechanisms of choice in the primate brain: a quick look at positive feedback, Modelling Natural Action Selection, J. J. Bryson, T. J. Prescott & A. Seth, pp. 45-52, AISB Press..
We consider the possibility that positive feedback loops are exploited by the brain in determining which action to perform at any given moment. We emphasise the need for, and requirements of, a controller that can exploit the potential benefits, and overcome the inherent pitfalls of using positive feedback for selection. We present the vertebrate basal ganglia as one possible solution to this control problem, and focus on basal ganglia involvement in the oculomotor system of the primate brain, presenting it as an example of how positive feedback and competitive dynamics are used synergistically to bring about changes in gaze. Finally we strengthen the case for involvement of positive feedback mechanisms in reflexive gaze control by demonstrating that a computational model of the oculomotor system is able to reproduce eye movement abnormalities present in sufferers of Parkinsonís disease - a disease that affects the basal ganglia, and consequently the control of positive feedback.
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