Reflexive priority of biological motion in attentional orienting: evidence from conflict resistance in complex visual settings

Humans involuntarily orient their attention to walking direction of biological motion (BM), a crucial skill for adaptive survival and social interaction. While previous studies have been limited to isolated BM displays, real-world scenarios typically include BM alongside multiple competing stimuli, hampering the translation of laboratory insights into practical applications. Here, we introduced simultaneously presented BM cues and other social (eye gaze) or nonsocial (arrow) cues into a modified central cueing paradigm, reassessing the reflexive nature of BM-induced attention from the perspective of conflict resistance. Results showed that the attentional orienting elicited by BM was robust enough to resist interference from peripheral arrows throughout the task yet interfered with central arrow processing. This unique asymmetric interference effect highlights the reflexive priority of BM over nonsocial cues. Additionally, mutual interference between BM and eye gaze suggests that different types of social cues trigger attentional shifts with a considerable degree of reflexivity. Based on an interference-resilient criterion, these findings together imply that social attention is supported by a specialized mechanism shared across various social but not nonsocial cues. This mechanism potentially enables us to instinctively prioritize and orient toward social signals amid competing nonsocial cues in complex real-world settings, with direct implications for designing signaling systems in safety-critical contexts and developing early diagnostic tools for sociocognitive disorders such as autism.