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. Author manuscript; available in PMC: 2009 Oct 26.

Published in final edited form as: IEEE Trans Biomed Eng. 2007 Jun;54(6 Pt 1):1016–1030. doi: 10.1109/TBME.2007.894629

(A & B) Horizontal components of left and right eye rotational velocity for the same chinchilla as Figure 1, Columns 2 and 3 (ch050506B), during 2Hz 50°/s peak sinusoidal horizontal head rotations without (A, t<55.7 sec) and then with (A, t>55.7 sec) prosthetic electrical stimulation pulse-frequency-modulated by horizontal head velocity. Only the left horizontal SCC electrodes were activated. Stimulus parameters: cathodic-first biphasic pulses, bipolar electrode pair in the left horizontal SCC ampulla, 150 μA/phase, 200 μs/phase, f_peak 300 pulse/s, f_baseline 100, C=5. Head rotation without electrical stimulation elicited no AVOR. Onset of electrical stimulation produced brisk, asymmetric horizontal nystagmus. (B) Slow phase nystagmus is already more symmetric in direction <20 sec after onset, tracking horizontal head velocity with a mean gain for the each eye similar to the mean response for normal animals (dashed gray line). (C) Mean±1SD cycle-by-cycle average for horizontal, LARP and RALP components for both eyes over the 17 cycles beginning at t=67 of the trial shown in A & B.

(A & B) Horizontal components of left and right eye rotational velocity for the same chinchilla as Figure 1, Columns 2 and 3 (ch050506B), during 2Hz 50°/s peak sinusoidal horizontal head rotations without (A, t<55.7 sec) and then with (A, t>55.7 sec) prosthetic electrical stimulation pulse-frequency-modulated by horizontal head velocity. Only the left horizontal SCC electrodes were activated. Stimulus parameters: cathodic-first biphasic pulses, bipolar electrode pair in the left horizontal SCC ampulla, 150 μA/phase, 200 μs/phase, f_peak 300 pulse/s, f_baseline 100, C=5. Head rotation without electrical stimulation elicited no AVOR. Onset of electrical stimulation produced brisk, asymmetric horizontal nystagmus. (B) Slow phase nystagmus is already more symmetric in direction <20 sec after onset, tracking horizontal head velocity with a mean gain for the each eye similar to the mean response for normal animals (dashed gray line). (C) Mean±1SD cycle-by-cycle average for horizontal, LARP and RALP components for both eyes over the 17 cycles beginning at t=67 of the trial shown in A & B.