Vestibulo-ocular

See also

oculomotor system

vestibular nystagmus

opto-kinetic movements

Definition

keeps the visual image fixed by moving the eyes when the head moves

Function

vestibulo-ocular movements = use vestibular input (semi-circular canals) to hold images stable on the retina during brief or rapid head rotation, i.e. it changes the head velocity signal into an eye velocity signal

opto-kinetic movements = the same for slower movements

stabilizing the fovea using the vestibular system is faster than waiting for information from the visual system

the gain of the vestibulo-ocular reflex (how much to move the eyes in relation to the head) is modifiably by experience

affected by damage to cerebellar flocculus or inferior olivary nucleus

Details

see http://thalamus.wustl.edu/course/audvest.html

if you move your head to the left

excite the left horizontal canal

inhibit the right horizontal canal

to keep your eyes fixed on the same point

fire the right lateral rectus and the left medial rectus

to move the eyes to the right

pathway

semi-circular canals -> vestibular nerve???

vestibular nerve -> vestibular nucleus in brainstem

left horizontal canal

right horizontal canal is inhibited, so doesn't send any signals

medial longitudinal fasciculus is important, apparently