Linear head displacement measured by the otoliths can be reproduced through the saccadic system.
Normal subjects seated on a moving cart have been submitted to horizontal linear accelerations in the frontal plane. They were shown an earth-fixed target at a distance of 63 cm before the onset of cart motion, which occurred in total darkness. They were asked to keep their gaze on the imagined target. The main result is that, in spite of a low gain otolith-ocular reflex, they could reproduce their motion with great accuracy by saccades (a small overestimation was, however, observed). It is concluded that otolith information is used by probably cortical spatial analysers which can derive a precise measurement of linear displacement and feed this information in the saccadic system.
Berthoz
A
A
Laboratoire de Physiologie Neurosensorielle du C.N.R.S., Paris, France.
Israël
I
I
Viéville
T
T
Zee
D
D
D000054:Acceleration; D005133:Eye Movements; D006257:Head; D006801:Humans; D009038:Motion; D010037:Otolithic Membrane / Q000502:physiology*; D012027:Reflex, Vestibulo-Ocular; D012438:Saccades; D012444:Saccule and Utricle / Q000502:physiology*