: This study verified how timing of sound effects affects the user's operation performance with interactive content, such as computer games. We conducted an experiment to test the hypotheses that (1) operation performance is slightly degraded if the sound effects lag behind the visual beat with "good" timing and (2) operation performance is substantially degraded if the sound effects lag behind the visual beat with "bad" timing, where the "visual beat" in interactive content is the repetition of periodic visual accents in visual images. Our findings indicate that a delayed timing of sound effects degrades the operation performance, but the degradation depends not only on the degree of delay of the sound effects, but also on how in tune the sound effects are with the visual beat.

Pupil response reflects sympathetic activity and recent research has begun to study pupil response as a stress indicator. It is thought pupil response may be used as an indicator of stress and emotion. This study investigated whether pupil size reflects liking and interest which are Kansei activities. Fifteen adult subjects with normal vision were tested. The subjects' pupil responses were measured while looking at 32 images in random order. The images were digital color photos projected on a computer monitor depicting 16 models. Each model was shown with two expressions: 8 images of happy faces and 8 of neutral faces, and 8 images of angry faces and 8 of neutral faces. The subjects rated their liking and interest for each image using 5 point scales. This revealed that pupil size was significantly larger while viewing images rated as 'dislike' than while viewing images rated as 'like', over a period between 5 and 10 seconds after stimulus onset. Pupil size didn't reflect interest but liking. The results suggested that subjects physiologically relaxed while looking at images they like.

Abstract:The objective of this research is to partly clarify how Kansei works for interface users through the experimental study about effects of user's Kansei excited by color information in user interface. Firstly, we discuss how Kansei can be understood and evaluated in the field of user interface. Then an experimental study is introduced. In the experiment a PC program of "mental-rotation in virtual 3D environment" was developed, in which the interface background color could be changed by designed beforehand or by user's favorable choose. We utilize 4 kinds of interface background colors as stimuli to the subjects in 4 groups, and quantitatively compare emotional reactions from two aspects of physiological response and subjective evaluation among the 4 groups. According to the results of experiment, the effects of user's Kansei are discussed in the relationship among stimuli information of interface, emotional reactions and operating behaviors. Finally, we propose possible approaches and new challenging topics in the study of Kansei supporting interface.