Visualizing Face Representations after Adaptation

A distorted perception from face adaptation has been reported broadly and robustly, and it is used for exploring face representation. While the effect of face adaptation is typically estimated based on changes in participants’ judgments regarding subsequent facial stimuli, we aimed to visualize participants’ mental representations of faces by using reverse correlation image classification—a psychological method for revealing representation (Mangini & Biederman, 2004). In the experiment, participants adapted to either attractive or unattractive faces for five minutes; following this, the averaged face (i.e., base face) of attractive and unattractive faces was presented for 20 seconds, and participants were asked to memorize it. After a five-minute filler task, participants were asked to judge which of two presented faces—that is, the base faces covered with the same noise pattern but inverted (white and black)—was more similar to their memorized base face. Each participant judged 450 face pairs, and based on their judgments, the noises of the selected and unselected stimuli were each averaged and used for visualizing the representation of each participant. The experiment included three conditions (attractive face adaptation, unattractive face adaptation, and no adaptation), and each was conducted over three days. The first day featured either the attractive or the unattractive face as the adaptation stimulus, and the next day featured the other face. The no-adaptation condition was performed one week after the first day. The results of the visualized images showed that the base face appeared more attractive after the participants had adapted to an unattractive face compared to after they had adapted to an attractive face. This method enables us to reveal how adaptation changes face representation visually. The visualized representation images are presented in our poster.