FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-63/14

Title and Subtitle: Nystagmus responses of the cat to rotation and to directionally equivalent and non-equivalent stimuli after unilateral caloric habituation

Report Date: August 1963

Authors: Collins WE

Abstract: Six cats were exposed to mild angular acceleration before and after an intervening serried 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 a decline in both the primary and the secondary caloric measures.

Responses to rotation following the caloric habituation showed almost no change, i.e., there was no apparent stimulus generalization. Differences in: (a) the patterns of nervous excitation elicited by unilateral and bilateral stimulation, and (b) intensity, were hypothesized as possible causes for the failure to obtain transfer. Additional unilateral caloric trials confirmed reports that the reduction of nystagmus is specific to the direction elicited during habituation trials.

Key Words: vestibular, nystagmus, habituation, transfer effects, sensory physiology

No. of Pages: 13