ABSTRACT
The vestibulo-ocular reflex (VOR) helps to stabilize the retinal image by rotating the eyes to compensate for movements of the head. An ideal VOR, that tries to compensate for any arbitrary movement of the head in three-dimensional space, would generate eye rotations at the same speed as, but in the opposite direction to, head rotation independent of the momentary rotation axis of the head. Electrical stimulation of single semicircular canals (SCC) nerves in animals has shown that SCC afferents induce eye movements roughly in the corresponding anatomical plane. Eye and head velocity data are plotted against time, with various inputs. Consequently, the vestibulo-ocular reflex produces eye movements toward the side with the lower tonic firing rate, resulting in fast phases toward the good ear. Both sides are connected via the vestibular commissures in an inhibitory manner.
