The influence of linear acceleration on optokinetic nystagmus in human subjects.

The influence of linear acceleration on optokinetic nystagmus (OKN) was studied in human subjects. Linear acceleration was applied to the subjects by means of the parallel swing and also by the transfer of the subjects in one direction, either right or left. The cortical form of OKN increased the frequency, amplitude, and eye speed of the slow phase. Of the three, the increase in eye speed was the most pronounced. The subcortical form of OKN was not only increased but was also disturbed by the linear acceleration. When the compensatory eye movement with linear acceleration and the slow phase of OKN were in the same direction, the nystagmus increased remarkably. Contrarily, when the two directions were opposed to each other, nystagmus was inhibited. These results proved that the otolithic organs are not only able to promote but also to inhibit visual function.