FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-63/03

Title and Subtitle: Observations of the elicitation of secondary and inverted primary nystagmus from the cat by unilateral caloric irrigation

Report Date: February 1963

Authors: Mohler SR, Dille RJ

Abstract: Vestibular stimulation by repeated unilateral caloric irrigation of cats occasioned the appearance of secondary, tertiary, and inverted primary nystagmus in some animals. These inverse responses were recorded with stimulus temperatures of 5, 23.5, and 53.5 C, applied for durations ranging 15-35 seconds. The inverse reaction most frequently obtained was the secondary nystagmus. Several possible explanations for the occurrence of the phenomena were examined. The findings appear related to habituation of the vestibular system, and thus have implications for vestibular adaptation in clinical situation and during air-vehicle maneuvers.

Key Words: adaptation, vestibular function, caloric nystagmus, sensory physiology, psychology

No. of Pages: 15