Early warning signals in motion inference

The ability to infer intention lies at the basis of many social interactions played out via motor actions. Here, we analyze data from experiments simulating an antagonistic game between an Attacker and a Blocker. Evidence shows early inference by Blockers of an Attacker move by ~100ms but the informational cues signaling the impending move remain unknown. We show that the transition to action has the hallmark of a critical transition that is accompanied by early warning signals. These early warning signals occur ~130 ms before motion ensues —showing a sharp rise in motion autocorrelation at lag-1 and a sharp rise in the autocorrelation decay time. These early warning signals correlate strongly with Blocker response times. We analyze the variance of the motion near the point of transition and find that it diverges in a manner consistent with the dynamics of a fold-transition. To test if humans can recognize and act upon these early warning signals, we simulate the dynamics of fold-transition events and ask people to recognize the onset of directional motion: participants react faster to fold-transition dynamics than to its uncorrelated counterpart. Together, our findings suggest that people can recognize the intent and onset of motion by inferring its early warning signals.