Cross-axis adaptation of the translational vestibulo-ocular reflex.
The adaptive plasticity of the translational vestibulo-ocular reflex (VOR) was investigated in rhesus monkeys after 2-h exposure to either vertical or torsional optic flow stimulation accompanied by lateral translation stimuli (0.5 Hz). Because of the inherent ambiguity in the otolith system for the detection of gravitoinertial accelerations, we hypothesized that cross-axis adaptation of the translational VOR during lateral motion would be preferentially selective for a torsional optic flow stimulus that would mimic a roll tilt movement. However, we found that both vertical and torsional adaptation was possible. Furthermore, there was no significant preference for whether the torsional adaptation was in phase or out of phase with the apparent tilt induced by the motion stimulus. These results suggest that, at least at 0.5 Hz, there seems to be no preferential, visually induced adaptive capacity of the otolith system for tilt/translation reinterpretation during motion. Like the rotational VOR, translational VOR appears to exhibit a general form of cross-axis adaptation that operates for different directions of optic flow stimulation.
Wei
M
M
Department of Anatomy and Neurobiology, Box 8108, Washington University School of Medicine, 660 South Euclid Ave, St. Louis, MO 63110, USA.
Angelaki
D E
DE
D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000502:physiology*; D019416:Head Movements / Q000502:physiology; D008253:Macaca mulatta; D009039:Motion Perception / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009483:Neuropsychological Tests; D017120:Nystagmus, Optokinetic / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D004856:Postural Balance / Q000502:physiology; D011187:Posture / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000502:physiology*