Pseudorandom rotational stimuli of the vestibulo-ocular reflex in humans: normal values of the transfer function

Pseudorandom binary rotatory stimulation is used to study the vestibulo-ocular reflex (VeOR) frequency response (from 0.01 to 0.64 Hz). Fifty-two normal subjects volunteered for this test. The transfer function's gain and phase, and the corresponding coherence function between slow phase eye velocity and head velocity were computed. According to the linearity hypothesis, the results match the sinusoidal stimulation studies. In both cases, the variability of the gain was higher than that of the phase shift. Identification of some parameters of the VeOR's mathematical model were performed, using the experimental results.