The Composite Effect for Inverted Faces is Reliable at Large Sample Sizes and Requires the Basic Face Configuration

Abstract The absence of the face composite effect (FCE) for inverted faces is often considered evidence that holistic processing operates only on upright faces. However, such absence might be explained by power issues: Most studies that have failed to find the inverted FCE tested 24 participants or less. Here we find that the inverted FCE exists reliably when we tested at least 60 participants. The inverted FCE was ∼ 18% the size of the upright FCE, and it was unaffected by testing order: It did not matter whether participants did the upright condition first (Experiment 1, n = 64) or the inverted condition first (Experiment 2, n = 68). The effect also remained when upright and inverted trials were mixed (Experiment 3, n = 60). An individual differences analysis found a modest positive correlation between inverted and upright FCE, suggesting partially shared mechanisms. A critical control experiment demonstrates that the inverted FCE cannot be explained by visuospatial attention or other generic accounts because the effect disappeared when the basic face configuration was disrupted (Experiment 4, n = 50). Our study shows that the inverted FCE is a reliable effect that requires an intact face configuration, consistent with the notion that some holistic processing also operates on inverted faces