Intrinsic potency of biological motion in guiding attention: A conflict-based assessment across autistic traits

Biological motion (BM) is a potent social signal capable of guiding human attention, a phenomenon termed social attention that underpins adaptive behaviour and interpersonal interaction. Although extensively studied in laboratory settings, social attention is typically examined using simplified, isolated cues, leaving unresolved whether it possesses reflexive properties distinct from nonsocial attention. This study developed a dual-cue paradigm that embedded oppositely oriented arrow cues within BM sequences, directly assessing the reflexive nature of BM-induced attention using a conflict-resilience criterion. Results confirmed that BM cues, despite being reduced to kinematic information within incongruent directional signals, robustly directed attention. Furthermore, this potency persisted even for local BM signals lacking global configuration but disappeared upon removal of essential biological characteristics, highlighting the crucial role of local motion cues in guiding attention under perceptual conflict. Crucially, BM-driven reflexive attention was negatively correlated with autistic traits. Individuals with higher autistic traits failed to utilize BM cues to direct attention, yet showed intact arrow-driven attention, manifesting specific deficits in social rather than nonsocial attention. These findings uncover an intrinsic processing advantage for social signals in complex contexts that appears compromised with increasing autism-like characteristics, providing a novel paradigm with promising implications for precisely assessing social attention ability in autism.