Authors: Morikawa, K., Matsushita, S., Tomita, A. and Yamanami, H.
Title: A real-lifeillusion of assimilation in the humanface: eye size illusion causedby eyebrows and eye shadow.
Journal(書誌情報): Frontiers in Human Neuroscience, 9:139 (2015).
Abstract: Does an assimilative illusion like the Delboeuf illusion occur in the human face? We investigated factors that might influence the perceived size of the eyes in a realistic face. Experiment 1 manipulated the position of the eyebrows (high or low), the presence/absence of eye shadow, and the viewing distance (0.6 m or 5 m), then measured the perceived eye size using a psychophysical method. The results showed that low eyebrows (i.e., closer to the eyes) make the eyes appear larger, suggesting that the assimilation of eyes into the eyebrows is stronger when the eye-eyebrow distance is shorter. The results also demonstrated that the application of eye shadow also makes the eyes look larger. Moreover, the effect of eye shadow is more pronounced when viewed from a distance. In order to investigate the mechanism of the eye size illusion demonstrated in Experiment 1, Experiment 2 measured the magnitude of the Delboeuf illusion at a viewing distance of 0.6 m or 5 m, with or without gray gradation simulating the eye shadow that was used in Experiment 1. The experiment demonstrated that the Delboeuf illusion is modulated by viewing distance and gradation in the same way as the eye size illusion. These results suggest that the eye size illusion induced by the eyebrows and the Delboeuf illusion involve the same mechanism, and that eye shadow causes the assimilation of the eyes into itself and enhances assimilation between the eyes and the eyebrows. 
著者Contact先の email: morikawa[at]
日本語によるコメント: 目と眉の距離(眉の位置が低いまたは高い),アイシャドウの有無、および観察距離(近条件0.6mと遠条件5m)の3要因が目の過大錯視に及ぼす効果を検証しました。心理物理学的手法で錯視量を測定した結果,高い眉の条件でのみ,観察距離が近い場合と比べて遠い場合ではアイシャドウによる目の過大視が増幅されました。このことは,観察距離が遠い場合にアイシャドウのグラデーションが目と高い眉の同化を促進させることを意味します。顔画像の代わりにデルブーフ錯視図形を用いた実験でも観察距離が遠い場合にグラデーションが同様の効果を生じました。これらの結果から,アイシャドウの錯視効果はデルブーフ錯視の原理に基づき,目と眉の知覚的同化を生じさせることが示唆されました。