In this study, we examined the effect of the duration of exposure on three facial evaluations: beauty, likability, and attractiveness of the whole face and facial parts (eyes, nose, and mouth). Participants were randomly assigned to four groups of different exposure duration conditions: 20-ms, 100-ms, 1000-ms, or without a time limit, and were asked to rate the beauty, likability, and attractiveness of the whole face and facial parts (eyes, nose, and mouth) on a 7-point scale. The results showed that all three evaluations of the whole face or facial parts were constant over exposure durations, while differences in likability among the stimulus emerged as the exposure duration was prolonged. We also analyzed the temporal changes in the contribution of facial parts to the three evaluations of the whole face with the data obtained in the same experiment. As a result, the eyes made a high contribution to all three evaluations of the whole face, and the mouth contributed to the likability and attractiveness of the whole face. These results suggest that facial beauty, likability, and attractiveness might be processed differently.

Perceptual grouping has been examined mainly by presenting visual stimuli in a 2-D field. In this study, we examined the characteristics of perceptual grouping in 3-D space by utilizing virtual reality (VR) technology. We used an elongated thin cylinder as the basic element. Participants were asked to find a predefined target made of five cylinders among the 1000 cylinders in the VR space. The orientation of the five cylinders of the target was varied systematically. The participant could move their head or body freely while searching. We found that in the VR space, the observers were sensitive to the structure in which the elements were oriented in parallel with each other. This structure was difficult to find in the 2-D field. These results indicate that in a 3-D space, the elements are perceptually grouped by utilizing the information from head and body movements which was not available while searching for a target in the 2-D field.