Influence of Objects Face-likeness on the Right-facing Preference

: Laterality is a bias in which humans prefer one side over the other. Previous research has shown laterality in facial direction and facial aspects; right-facing faces are preferred over left-facing faces, indicating a rightward dominance. Right hemisphere is specialized for face recognition, and facial parts of a right-facing face are located on the left side; hence right-facing face is expected to have higher perceptual fluency. This study investigated the relationship between the object’s face-likeness and the preference laterality and the difference in perceptual fluency depending on the object’s orientation, using psychophysical experiment and EEG measurement. As a result, right-facing preference was revealed only for face-like objects. In addition, it was shown that the perceptual fluency of right-facing objects was higher than left-facing objects, regardless of face-likeness. These results suggest that preference laterality is due to the influence of a) facial information processing mechanism and b) cognitive bias acquired through experience.