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

## TL;DR

Humans instinctively prioritize attention to biological motion over nonsocial cues, even in complex environments, suggesting a specialized mechanism for social signals.

## Contribution

The study reveals a reflexive priority of biological motion in attentional orienting that resists interference from nonsocial cues.

## Key findings

- Attentional orienting to biological motion resists interference from peripheral nonsocial cues like arrows.
- Biological motion and eye gaze mutually interfere, indicating shared reflexive mechanisms for social cues.
- A specialized mechanism supports social attention, distinct from nonsocial cue processing.

## Abstract

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.

Humans possess an innate ability to direct their attention to walking direction of biological motion (BM), which plays an essential role in adaptive functioning and interpersonal interaction. Traditional studies concerning such fundamental capacity have relied on simplified paradigms with isolated cues, neglecting the fact that real life is crowded with multiple directional cues where efficient attentional orienting can be a matter of safety. The current study uncovers, for the first time, that this attentional orienting triggered by BM is reflexive enough to withstand conflict from concurrently presented nonsocial cues (i.e., arrow) and even to progressively affect their processing. Together with the rapid interference observed between social cues (i.e., BM and eye gaze), these findings shed light on a shared mechanism specialized for social but not nonsocial attention, broadening the understanding of how humans instinctively prioritize social signals in the complicated real world. Beyond theoretical insights, this work is highly relevant for advancing designs of attentional guidance systems in human–computer interface or safety-critical settings, and offers ecologically valid approaches to early autism diagnosis.