Primary Visual Cortex Activity along the Apparent-Motion Trace Reflects Illusory Perception
The four panels correspond to four ROIs that were defined in V1 by the respective conditions. To determine the ROIs for the three mapping conditions—upper, middle, and lower—the relevant condition was contrasted with the remaining two mapping conditions in a conjunction analysis (e.g., upper > lower and upper > middle). For the real-motion ROI, the real-motion condition was contrasted with the upper and lower mapping conditions (conjunction analysis). The bars designate percentage signal change of the peak response relative to baseline for the different conditions (see Materials and Methods). The hatched bars are activations from runs with passive viewing only, and the solid bars are from runs with center task. For both the real-motion and middle ROI, the response to the apparent-motion stimulus is significantly larger than the response to the flicker squares. This is not the case for the upper and lower ROIs. Error bars correspond to standard errors of the mean.