Nystagmus Responses of the Cat to Rotation and to Directionally Equivalent and Non-Equivalent Stimuli After Unilateral Caloric Habituation

Abstract

Six cats were exposed to mild angular accelerations before and after a series of 15 caloric irrigations. All trials were in total darkness. Slow-phase displacement of the eyes, beat-frequency, and duration of nystagmus were scored. All 3 measures reflected declines in both the primary and the secondary reactions during the course of caloric irrigations. Responses to rotation following the caloric habituation showed almost no change; i.e. there was no apparent stimulus generalization. Some possible causes for the failure to obtain transfer were examined. Additional unilateral caloric trials confirmed reports that the reduction of nystagmus is specific to the direction elicited during habituation trials.