Inhibitory and promoting effects of subliminal pendular rotation on optokinetic nystagmus in man.

The influence of vestibular stimulation by subliminal pendular rotation on the optokinetic nystagmus in normal human subjects is discussed. Cortical OKN with pendular rotation was promoted in three indexes--eye speed, frequency, and total amplitude. The subcortical OKN increased markedly when the slow phase of OHN and the compensatory eye movement resulting from the pendular rotation were in the same direction. However, it was inhibited when the two directions were mutually opposed. From the results obtained in the present experiment and in the previous study by the author, it can be concluded that the vestibular organs' effect on visual function is not only promotive but also inhibitive.