Abstract
In VSS2006, we reported a brain-damaged patient whose perception of race was selectively impaired (Koyama et al 2006). The patient also demonstrated that her perception of race largely depends on the surface properties of the face (e.g., convexes and concaves). On the other hand, a study showed that the perception of sex depends on the outline of the face and face parts (e.g., Takahashi et al. 1996). Based on the above studies we hypothesized that the perception of race depends more largely on the low spatial frequency channels whereas the perception of sex depends more largely on the high spatial frequency channels. In order to test the hypothesis, we tested the normal subjects' performance in race and sex classification tasks with high-pass and low-pass filtered pictures. Nineteen subjects participated in the experiment. We used 56 pictures from JACFEE (Matsumoto & Ekman 1988) for the stimuli. There were 3 types of pictures which were made from the same 56 pictures: (1) original grayscale pictures, (2) high-pass filtered pictures, and (3) low-pass filtered pictures. The subjects participated in the race and sex classification tasks. In the race classification task, a picture was presented in a 21-inch LCD display and the subject judged whether the person in the picture would be Asian or Caucasian. The same pictures were used in the sex classification task, and the subject judged whether the person in the picture would be male or female. As predicted, the subjects performed better with the low-pass filtered pictures in the race classification task whereas they performed better with the high-pass filtered pictures in the sex classification task. The results supported the hypothesis that the perception of race depends more largely on the low spatial frequency channels whereas the perception of sex depends more largely on the high spatial frequency channels.
KAKENHI “Face perception and recognition” 21119507.