The high frequency limit of the fundamental vestibulo-ocular reflex

The high frequency limit of the image-stabilizing trineuronal vestibulo-ocular reflex is very difficult to assess experimentally, as the necessary accelerations are extremely high. We chose to examine fistulae of the bony horizontal semicircular canal. Oscillating pressures of between 3 and 40 Hz were applied to the fistula, and the fast pendular eye movements were registered by electronystagmography. Above 15 Hz there was no regular reaction. Up to 15 Hz the eye movements corresponded to the alternating pressure stimulus upon the fistula. Up to 11 Hz the ocular reaction was very strong, with calculated acceleration values near the dynamic limit of the bulbus and eye muscles. The capacity of the vestibular organ has often been underrated. In view of previous investigations and our own experiments it seems justified to set the frequency limit of the fundamental vestibulo-ocular reflex at at least 10 Hz.