Control Strategies in the Eye-Head Coordination System

The aim of this paper is to outline a model of the eye-head system and some of its control strategies. To formulate such a model, the eye-head system was stimulated with random or periodic visual targets. Coupling between the eye and head motor commands was evident in the experiments performed, and this was also found to be the case for acoustic and tactile stimuli. Further experiments were performed to investigate whether the central nervous system (CNS) would be able to overcome the relative lack offlexibility shown by the model of the eye-head control system initially proposed. These experiments, in which it was required to execute independent eye-head movements towards two simultaneous targets (visual and acoustic), showed an impaired performance, indicating that an overcoming action by the CNS is not always possible. The findings are interpreted in terms of an interaction between a "hardware" low-level controller and a "software" high-level decisionmaker.