Effects of the noise level on induced motion

Motion in a part of the field induces motion in an adjoining region. In this study, it was investigated how the noise level affects induced motion of a counterphase flickering (target) grating due to adjacent drifting (inducer) gratings. It was shown that at low noise levels, motion contrast occurred, and at high noise levels, motion assimilation occurred. When the noise level was randomly set for each trial, the adaptive change with the noise level was also observed. The result suggests that the adaptive change occurs for a short period. It was also found that noise for the target as well as noise for the inducers contributes to the effect of noise on motion induction. It suggests that the overall noise level is crucial for the effect. The study provided evidence that motion integration changes from a spatially band-pass operation to a low-pass operation as the signal-to-noise ratio (SNR) decreases.