FIG. 8.

A–C Mean ± SD eye and (inverted) head angular velocities of a normal rhesus monkey (F234RhD) during head impulse rotations (1,000 °/s² to a peak head velocity of 150 °/s) in darkness, about the horizontal (A), left anterior/right posterior (LARP, B), and right anterior/left posterior (RALP, C) semicircular canal axes. Standard deviation of each trace at each time point is <10 °/s. Data are truncated at the onset of the first nystagmus quick phase. D–F Same monkey (F234RhD) after bilateral intratympanic gentamicin and electrode implantation in left labyrinth, with MVP pulsing at baseline stimulation rate of 94 pulses/s on each channel but not modulating with head rotation. Responses are minimal, indicating failure of the VOR. G–I Same animal with motion-modulated MVP input at first day of MVP modulation on. J–L Third day response with improvement of misalignment. M–O Seventh day response with further improvement of misalignment, but not significant improvement of asymmetry (P > 0.05). Head movement traces are inverted for comparison to eye data. Asterisks indicate head rotations that excite the left labyrinth. (By the convention used to describe 3D movements, rightward eye movements are negative, while responses to exciting the LA and LP SCCs are positive).