Toward ecological validity in biological motion perception : dissociating real-time and video stimuli

Abstract

Traditional laboratory settings often fail to capture the dynamics of real-world social cognition. To address this gap, a novel experimental setup was developed that minimizes the confounding effects between real and video-based stimulus presentation by using a transparent OLED screen to display live human actions in the visual periphery. This allowed for direct comparison of “real” (live) and video actions under controlled conditions. Attentional load (high/low), stimulus type (real/video), and action type (actions with response-eliciting capacity, actions without response eliciting capacity, no peripheral action stimuli) were systematically varied. Behavioral results showed greater distraction from real actions than video counterparts, especially under low-load conditions. EEG analyses (ERP and cortical oscillations) revealed distinct neural patterns for real versus video actions. Notably, neural differences emerged even in the absence of visible stimuli when the actor’s physical presence was known in the live session, indicating that presence alone is enough to modulate brain responses. Contrary to expectations, actions with higher social engagement potential did not capture more attention, possibly due to interaction constraints. The findings highlight the role of physical presence and contextual realism in shaping cognitive processing and underscore the value of ecologically valid paradigms in social neuroscience.