Semicircular canal nerve eye and head movements. The effect of changes in initial eye and head position on the plane of the induced movement.

Abstract

When individual semicircular canal nerves are stimulated in the alert cat, dog, monkey, and rabbit, eye and neck muscles are strongly activated and characteristic head and eye movements are induced. 1-4 From the normal position the head and eyes move in planes parallel to the plane of the canal whose nerve is stimulated. 3,4 Since the optic axis (the line which passes through the center of the cornea and the center of rotation) in man is the same as in the monkey, 5 it is likely that similar eye and head movements would be induced by individual semicircular canal nerve stimulation in humans. The eye movements induced in the monkey by stimulation of the semicircular canal nerves on the left side with the head restrained are shown in Fig 1. Head movements in similar planes are induced when the head is free to move. In view of the mobility of