Quantitative measurements of driver's motion after-effect

In this article, the motion after-effect (MAE) is treated, which takes place when one drives on a highway for a while. One's sensitivity to motion in the direction of moving stimulation is reduced, resulting in misjudgements of cursing speed and sometimes in car accidents, especially when the driver intends to slow down the speed of the car. We have developed a system foe systematic measurement of MAE under various conditions; temporal frequency of stimulus, spatial frequency of stimulus, stimulus with depth cues, complex stimulus for the central as well as for the peripheral parts of the retina, and so on. The degree of MAE, the duration of MAE, was measured in terms of the duration of MAE. We obtained the following results: the degree of MAE is strongest around 5Hz; the degree of MAE extended lip to some value as the period of stimulation got longer; for low spatial frequencies, the duration of MAE decreased as the speed increased, and rose for high spatial frequencies; and so on. We paid attention to the two mechanisms of the visual system; central vision and peripheral vision. We synthesized a complex stimulus pattern consisting of two regions, one of which is to stimulate the central region of the retina and the other the peripheral region. It was possible to reduce the duration of MAE by showing a stimulus moving in the opposite direction of the periphery.