Self-reference modulates the perception of visual apparent motion

Visual apparent motion is a perceptual illusion where sequentially presented static stimuli containing no physically continuous motion are perceived as moving. In the current study, we examined whether and how self-reference, as a typical high-level information processing, could modulate perceptual categorization of the apparent motion in Ternus display, even when self-reference is task-irrelevant. Two frames were consecutively presented, with the first frame consisting of two identical stimuli (e.g., two rectangles) on the leftmost and the middle positions and the second frame consisting of two stimuli on the middle and the rightmost positions. Depending on the inter-stimulus interval (ISI) between the two frames, the display could be perceived as showing Element Motion (EM), with the peripheral stimulus moving from one side to the other while the middle stimulus remains stationary or flashes briefly at the middle position, or Group Motion (GM), with both stimuli appearing to move as a whole. Participants were tested in this configuration and then learned to associate different labels (Self, Friend, Stranger) with geometric shapes (Circle, Rectangle, Triangle). They were tested again in the new configuration. Results showed that after association (vs. before association), participants were more likely to perceive the Ternus display of self-associated shapes as GM, but this effect did not appear for friend-associated or stranger-associated shapes. Self-referential processing spatially "glues" the two stimuli in a frame with the concept of "Self," leading to a more dominant percept of GM.