Linking perceptual animacy to attention: evidence from the chasing detection paradigm.

Perceptual animacy describes the tendency of human observers to interpret motion cues that suggest an interaction between two objects in anthropomorphic terms, such as social causation or intention. Recent studies established a chasing detection paradigm that allows a psychophysical measurement of animacy. Here, we present several variants of the chasing detection paradigm in order to investigate how attention contributes to the detection of animate motion. We show that detection accuracy (Experiment 1a) and response latency (Experiment 1b) depend on the physical set size, suggesting that an attention-demanding serial search is necessary to detect a chase among distractors. Experiment 2 replicates these findings with a manipulation of attentional set size. In Experiment 3, we investigated the efficiency of chasing detection. Therefore, we contrasted the chasing detection task with a task that required the detection of identically colored objects. Search slopes for chasing objects were twice as large as search slopes for identically colored objects. In sum, these results show that chasing cues do not pop out of a display but require an effortful visual search through subsets of all possible items.