Visual search for people among people

Humans can effectively search visual scenes by spatial location, visual feature or whole object. Here, we show that visual search can also benefit from fast appraisal of relations between individuals in human groups. Healthy adults searched for a facing (seemingly interacting) body-dyad among nonfacing dyads, or vice versa. We varied the task parameters to emphasize processing of targets or distractors. Facing-dyad targets were more likely to recruit attention than nonfacing-dyad targets (Experiments 1-2-4). Facing-dyad distractors were checked and rejected more efficiently than nonfacing-dyad distractors (Experiment 3). Moreover, search for an individual body was harder when it was embedded in a facing, than a nonfacing dyad (Experiment 5). We propose that fast grouping of interacting bodies in one attentional unit is the mechanism that accounts for efficient processing of dyads and for the inefficient access to individual parts within a dyad.