Primary, secondary, and caloric nystagmus of the cat following habituation to rotation.

Abstract

Ten cats were exposed to a series of threshold accelerations and subthreshold decelerations. Unilateral caloric irrigations, provoking nystagmus in the same direction as threshold rotational stimuli, preceded and followed the set of accelerations. A marked nystagmus response decline, characterized by specific changes in early trials, resulted from repeated rotation. Although neither duration nor total slow-phase eye displacement to caloric stimulation was affected, the intervening rotational experience produced some reduction in the frequency of the nystagmic beats. Secondary nystagmus activity appeared closely related to preceding primary reactions. Caloric responses to vestibular stimulation may not give an accurate indication of a S''s (subject''s) state of adaptation to "practiced" levels of angular acceleration.