Two faces of holistic face processing: Facilitation and interference underlying part-whole and composite effects

Holistic processing, a strong tendency to process multiple features together, is regarded as a hallmark of face perception. Holistic effects can be revealed by several tasks, including the part-whole task, standard composite task, and complete composite task. Although holistic effects are readily observed using these tasks, the lack of correlations among these effects and the mixed findings across these tasks when examining the effects among various populations or manipulations pose questions about how these effects should be understood. We distinguished facilitation and interference effects within the holistic effects in the complete composite task and found that the holistic effect in the part-whole task appeared to be correlated with facilitation but not interference in the complete composite task, whereas the holistic effect in the standard composite task was correlated with interference but not facilitation in the complete composite task. These findings suggest that clarifying the roles of facilitation and interference is critical for understanding holistic face processing.