Adaptation Of Horizontal Semicircular Canal Responses

Abstract

The torsion pendulum model predicts semicircular canal responses when angular accelerative stimuli are relatively brief, but certain discrepancies appear when accelerations are sustained for a longer time. A recently proposed revision of the torsion pendulum model accounts for many of these discrepancies on the basis of a short-term adaptation process. The revised model was tested by comparing its predictions with the observed responses of subjects exposed to a series of prolonged accelerations. The model described these data fairly accurately, although minor discrepancies remained, suggesting the existence of additional adaptation processes. A new method is described for measuring the adaptation process described by the model. This method is based on a single measurement that can be obtained with relative ease for either nystagmus or sensation responses.