Abstract
Introduction: Faces are recognized best when individuals look close to their own distinct preferred fixation location (PFL), with some preferring to look down toward the nose tip and mouth while others prefer to look up toward the eyes (Peterson & Eckstein, 2013). Here, we investigate whether individual differences in the preferred point of fixation modulate the composite face effect (CFE). Specifically, we test whether the variation in the strength of the CFE for top and bottom face halves depends on the PFL. Methods: Sixteen eye-lookers and sixteen nose/mouth-lookers were screened through a free eye movements face identification task from a pool of 126 observers. The selected observers then completed a free eye movement face identification task with 4 composite faces. A subsequent parts matching task consisted of observers matching top or bottom face halves (block dependent) across two sequentially presented aligned or misaligned (block dependent) composite faces (50% matched, 50% unmatched, 200 msec.). Across trials, observers maintained their fixation at the mean preferred fixation point of their group or the mean of preferred fixation point of the other group. Results: We conducted a 3-way repeated measures ANOVA on the CFE (PCmisaligned – PCaligned) with the looker type, fixation location and the half being judged as factors. We found a significant main effect of the half being judged (F (1,120) =29.26, p << 0.05) and a significant interaction between the looker type (eye vs. nose/mouth looker) and half being judged (top vs. bottom; F (1,120) = 8.74, p = 0.0037). A post-hoc Welch test with FDR correction confirmed that eye lookers showed a significantly stronger CFE at the top half as compared to the bottom half (t (62) =2.94, p = 0.0046). Conclusion: The findings suggest that the preferred point of fixation might modulate the locus of the Composite Face Effect.