Opposite effects of putting on and taking off glasses on face identity perception

Wearing glasses can alter various facial appearances, potentially interfering with face processing during person identification. Although prior research has examined their effects on face recognition and matching, much less is known about how wearing glasses influences the perceptual detection of changes in face identity. This study examined how wearing glasses influences face identity perception. In Experiment 1, 45 participants judged whether two sequentially presented faces were the same individual. The results indicated that putting on and taking off glasses had opposite effects on face identity change detection relative to not wearing glasses: faces were more likely to be perceived as the same identity when glasses were taken off between successive faces, whereas a greater degree of facial similarity was required for two faces to be judged as the same identity when glasses were put on. Experiment 2 employed the same task but shifted the glasses upward. Under this manipulation, the effects observed in Experiment 1 were very weak or eliminated. Collectively, these findings demonstrate opposite effects of putting on versus taking off glasses on face identity perception, which are most pronounced when glasses are properly worn.