Abstract
The mutual interrelationships between the visual-ocular reflex (ViOR) and the vestibulo-ocular reflex (VeOR) are not completely understood yet. Optokinetic nystagmus (OKN) during ViOR was produced by rotating light stripes (Jung type). The whole visual field OKN, peripheral OKN, foveal OKN and hemianopsic OKN were produced with a Miyoshi-Shirato device.
Rotating nystagmus (RN) during VeOR was induced by a rotating chair.
OKN and RN were applied simultaneously to the same subject in the same direction and then in the opposite direction and vise versa.
1) The combined velocity of OKN and RN in the whole visual field was always constant, regardless of the phase of rotation.
2) When the peripheral OKN and RN were combined in the same direction, the velocity of the peripheral OKN was increased about 10-20%, compared to that in peripheral OKN only.
In contrast, when the peripheral OKN and RN were combined in the opposite direction, the velocity of the peripheral OKN was decreased about 10-20%.
3) In most of the subjects it was difficult to produce foveal OKN, and when RN was added to this OKN, the foveal OKN was not changed at all or suppressed in all four phases of rotation.
4) When the hemianopsic OKN and RN were combined in the same direction, the velocity of the former was increased and when they were in the opposite direction, the velocity of the former was decreased, regardless of whether hemianopsic OKN was temporal or nasal, foveopetal or foveofugal.
