Exploring Spatial Interference Effects in Social and Non-Social Targets: A Conditional Accuracy Function Analysis

Recent research using the spatial interference paradigm reveals qualitative differences in congruency effects between gaze and arrow stimuli. Arrows typically produce a standard congruency effect (SCE), with faster responses when the target direction matches its location. In contrast, gaze stimuli often result in a reversed congruency effect (RCE), where similar conditions yield slower responses. To explore this, we analyzed accuracy across reaction time bins using the Conditional Accuracy Function (CAF) and hierarchical linear mixed modeling. Data from sixteen experiments, 705 participants, comparing cropped eyes and full faces as social stimuli with arrows as non-social stimuli, were synthesized into three models. Results showed that for non-social stimuli, incongruent trials had lower accuracy in the fastest bin compared to later bins, while congruent trials maintained stable accuracy. For social stimuli, the fastest responses exhibited reduced accuracy for both conditions, with congruent trials performing even worse than incongruent ones. These findings suggest that gaze targets engage in additional processing, besides attentional capture, during earlier stages.