This figure shows the results of the PLV analysis for second-interval stimuli (S2).

<p>No PLV differences between contours and non-contours were found for first-interval (S1) stimuli. <b>A</b> Plot showing time and frequency ranges of PLV differences as obtained by randomization tests (p-values). The p-values refer to the number of electrode pairings where PLV was significantly increased (red) or decreased (blue) for contour compared to non-contour stimuli. Prominent effects were found within lower and upper theta frequencies as indicated by black rectangles (θ₁, θ₂). <b>B</b> Shows the number of electrode pairings where PLV was larger in the contour compared to the con-contour condition minus the number of electrode pairings where PLV was larger in the non-contour compared to the contour condition. <b>C</b> Waveforms showing the number of electrode pairings with significant PLV differences in the contour and non-contour conditions, as a function of time. A large number of couples exhibited a pre-stimulus PLV decrease (θ₁, left) and a post-stimulus PLV increase (θ₂, right) for contour- compared to non-contour stimuli. <b>D</b> Head topographies showing the number of pairings with significant PLV increases or decreases that a given electrode enters into (upper row). A subset of these couplings, where p<.01 for PLV differences, are illustrated by lines connecting electrodes (lower row). The θ₁ effect (left) involved mainly frontal and parieto-occipital electrodes, whereas the θ₂ effect (right) was found at frontal and temporal electrodes.