A web-based spot-the-difference paradigm for studying social information processing in naturalistic visual scenes

This pilot study introduced and assessed a novel web-based spot-the-difference paradigm for investigating social information processing in naturalistic visual scenes. The task systematically manipulated both the presence versus absence of social elements (i.e., social figures) and the location of the target difference (social vs. nonsocial regions). Participants identified differences via mouse clicks while their eye movements and mouse trajectories were recorded simultaneously throughout the task. In Study 1, behavioral and eye-tracking data supported the task's sensitivity to social salience, as evidenced by differences in accuracy and reaction times for social versus nonsocial target differences, along with consistently greater gaze fixation on social regions regardless of where the target difference appeared. In comparison, mouse-tracking data reflected more goal-oriented behavior, with cursor trajectories more frequently falling within regions containing the target difference. Study 2 further showed that this paradigm was sensitive to individual differences in autistic traits. Participants with higher autistic trait scores exhibited slower responses specifically in social contexts, irrespective of the location of the target difference, suggesting increased cognitive demands during social information processing. However, their gaze and mouse movement patterns remained comparable to those with lower autistic trait scores. Collectively, these findings suggest that this paradigm may provide a scalable and flexible approach for studying social cognition beyond traditional laboratory settings and may help capture the dynamic unfolding of social information processing through integrated multimodal data.