Abstract
Perceptual grouping is of critical value in understanding the world since it uncovers visual structure at the perceptual stage. Its occurrence is classically associated with physical principles which contribute to catch physical structure. However, for some visual scenes social properties are key factors in shaping another side of the visual structure -- social structure. Thus, it is equally important to explore whether human can perceive objects as an organized group according to social cues. To explore this issue, in the current study two fundamental human relationships, cooperation and competition were considered, which were constructed by forward replaying human trajectories when two agents (predators) were doing cooperative and competitive chase for a common target. Each relationship was compared with its backward replay (the control condition), which has poor impression of the social relationship between two agents but provides appropriate controls for low-level differences. Measuring the grouping effect by its induced attentional consequences, we found: 1) in the cooperative relationship, the attention automatically spreads within the group constituted by two agents, such that the cued agent facilitates the response for the target appearing at the other agent, relative to the control condition; 2) while for the competitive relationship, the attentional effect on two interactive agents has no difference compared with the control condition wherein the two agents aren’t perceptually grouped. Even though other alternatives were ruled out (i.e., smaller distance and higher speed), the null grouping effect still existed for competitive relationship. These results suggested that the cooperative but not the competitive relationship rooted in dynamic chase can drive perceptual grouping of objects. Further, these findings implicate that social information can get involved in visual cognition at an early stage.
Meeting abstract presented at VSS 2013