Perceived coordinated biological motion sequences warp time perception.

Collective motion requires coordinated movements of multiple individuals, such as people walking in the same direction and in temporal synchrony. It provides a salient social signal closely linked to coordinated group action and social cohesion. Previous research has shown that the human visual system is highly sensitive to such coordinated biological movement, efficiently representing multiple moving agents as a unified spatial entity. While coordinated biological motion also unfolds over time, it remains unclear how its temporal dynamics are processed. Here, we asked participants to complete a temporal comparison task using multiple point-light walkers, in which they indicated which of two sequentially presented displays (coordinated or uncoordinated) had a longer duration. The results revealed that coordinated biological motion sequences, defined by temporal synchrony (i.e., matched step phase) and spatial alignment (i.e., common walking direction), were perceived as shorter in duration than uncoordinated counterparts, in which both temporal synchrony and spatial alignment were disrupted. This effect persisted even when the biological motion was scrambled, but disappeared in static displays. Crucially, it was not attributable to low-level spatial perceptual organization, as it remained robust across varied stimulus configurations. Interestingly, this effect was absent in non-biological motion and object motion, suggesting that the change in perceived duration is specific to high-level bio-social signals. Moreover, the effect was stronger for temporal synchrony than for spatial alignment. These findings point to a specialized mechanism for time perception tuned to coordinated group movement, highlighting the influence of higher-order social dynamics on the subjective experience of time.