Visual stimuli and results of experiment 2. A , Target stimuli of experiment 2 consisted of two quarter arcs aligned symmetrically or asymmetrically over visual meridians. B , fMRI time courses extracted from ROIs averaged across participants and different scanning days. Error bars indicate SE among participants. C , Estimated BOLD response amplitudes within the ROIs. Error bars indicate SE. *p < 0.05; **p < 0.025 (one-tailed t test). The strongest responses were observed in the diagonal (point-symmetrical configuration) stimulus despite of the remotest distance between the circular elements both in the visual field and on the early cortex. This enhancement was disappeared when the elements were arranged asymmetrically (the control condition).