Investigating the gaze-driven reversed congruency effect in the spatial Stroop task: A distributional approach

This study investigated how social (faces and eyes) and non-social (arrows) stimuli modulate attentional orienting in a spatial Stroop task, using a distributional approach. Data from 11 studies (N = 705) were analysed through cumulative distribution functions (CDF), delta functions, and polynomial trend analyses. Three models were applied: (1) a reaction time (RT) model comparing social (faces and eyes) vs. non-social stimuli under congruent and incongruent conditions, (2) a delta model assessing conflict effects across quantiles, and (3) a trend model identifying specific delta function patterns. Non-social targets produced a standard congruency effect (SCE), with faster responses in congruent trials but no consistent conflict reduction across the distribution. In contrast, social stimuli exhibited a reversed congruency effect (RCE), with faster responses in incongruent trials, emerging from the second quantile onward and minimal conflict among the fastest responses. Social targets exhibited comparable reaction times in the RT model and similar early delta plot patterns, suggesting shared initial perceptual and attentional mechanisms between faces and eyes. However, faces eventually induced a larger RCE, possibly due to their more complex configuration. These findings highlight distinctive patterns between social and non-social processing in the spatial Stroop task.