Amplitude and frequency prediction in the translational vestibulo-ocular reflex

Abstract

The goal of this study was to assess the effect of amplitude and frequency predictability on the performance of the translational vestibulo-ocular reflex (tVOR). Eye movements were recorded in 5 subjects during continuous vertical translation that consisted of a series of segments with: 1) 3 amplitudes at constant frequency (2 Hz) or 2) 3 different frequencies (1.6, 2, 2.5 Hz). Stimulus changes were presented in a pseudo-random order. We found that there was little change in the tVOR immediately after an unexpected stimulus change, as if eye velocity were being driven more by an expectation based on previous steady-state motion than by current head translation. For amplitude transitions, only about 30% of the eventual response change was seen in the first half cycle. Similarly, a sudden change in translation frequency did not appear in eye velocity for 70 ms, compared to a 8 ms lag during similar yaw rotation. Finally, after a sudden large decrease in frequency, the eyes continued to track at the original higher frequency, resulting initially in an anti-compensatory tVOR acceleration. Our results elucidate further the complexity of the tVOR and show that motion prediction based on prior experience plays an important role in its response.

Somatosensory Influence on Platform-Induced Translational Vestibulo-Ocular Reflex in Vertical Direction in Humans

“…Independent of stimulus frequency, the gain of the eye movements was lower than necessary for compensation with a total mean value of 0.64 and 0.74 for experiments A and B, respectively. This is consistent with the reported gain spectrum (0.42-0.75) of earlier reports (6,(31)(32)(33). Interestingly, the mean time lag of 40 ms in the current study is maintained during an experimental sequence even when stimulus frequency decreased below 1 Hz.…”

Perspectives on Aging Vestibular Function

“…Linear VOR responses to fore-aft accelerations were smaller in older adults than in younger adults ( 31 ), demonstrating that the otolith responses to movement and to sound/vibration show a similar pattern of decline with age. The linear VOR has been implicated in anticipatory eye movements and a decline in otolith function may contribute to abnormal gaze stability during repetitive behaviors such as walking ( 32 ).…”