The experiment began with a preliminary preference-rating task (Figure 2). In each trial, a picture of food was presented at the center of the display, along with a visual analog scale (VAS). The height and width of the VAS was 14.91 and 2.06°, respectively. The left end of the VAS indicated that the picture did not look delicious, whereas the right end of the VAS indicated that the picture looked delicious. Participants were asked to report their perceived deliciousness by clicking on a corresponding position on the VAS. The preference-rating task consisted of 10 practice trials (five trials for each food category) followed by 80 experimental trials (40 trials for each category). The presentation order of the pictures was completely randomized.