Primary Visual Cortex Activity along the Apparent-Motion Trace Reflects Illusory Perception
(A) Left occipital cortex of subject HP (all five subjects are shown in Figure S2) with superimposed contrast maps indicating the cortical representation of the stimulus positions: upper (yellow), t(1445) > 15; middle (orange), t(1445) > 12; and lower (red), t(1445) > 9.3 (all p << 0.001). For comparison, the patches from experiment 1 (see Figure 1) are marked with dotted lines.
(B) Cortical activation maps for apparent motion (green) and real motion (blue). In this case, apparent motion is contrasted with the flicker control condition (apparent motion > flicker in V1: t > 3.6, p < 0.0004); real motion is compared to fixation baseline (real motion > baseline in V1: t > 18.6, p << 0.001). The white line indicates an example of a significant (t > 2.2, p < 0.05) contrast conjunction: (middle > upper) and (middle > lower) and (apparent motion > flicker).
(C) BOLD activity profile of the region indicated by the white line in (B). Bars indicate average activity during the respective conditions expressed in beta weights from a GLM analysis.