A Reexamination of “Neck Reflex” Eye Movements in the Rabbit

Abstract

Horizontal eye movements of rabbits were recorded during sinusoidal oscillation (15–40°, pk-pk; 0.1–8 Hz) and step displacement of the body in yaw about a fixed head. Modulated, slow-phase eye movements followed all frequencies of stimulus with relatively invariant amplitudes (2–4°). Saccadic movements, up to 17°, accompanied all frequencies of oscillation and particularly step displacements. Saccadic amplitude was unrelated to measurable characteristics of the stimuli but was a function of arousal. The latency of any eye movement was a minimum of 80 msec. It is concluded that none of the observed eye movements provide stabilization during head movements but are evidence of the contribution of neck information to general mechanisms of whole body orientation.