抄録
Because of simplicity, subjective evaluation methods with questionnaires have been used conventionally to assess biological effects of viewing visual images. However, these methods have low objectivity and low reproducibility, and it is difficult to evaluate the effects as a time series. On the other hand, physiological indices based on such as electrocardiography, photoplethysmography, and electroencephalography have commonly been used to evaluate the effects objectively and continuously. However, physiological indices may include psychological effects as well as physiological effects, which have been considered little in the conventional studies. In this study, therefore, in order to remove the psychological effects from the physiological indices as much as possible and to extract the physiological effects such as eye strain or visually induced motion sickness, we performed the experiment in which the same video was shown multiple times to subjects with an expectation of attenuation of the psychological effects by adapting to the experiment. From the experimental result, a physiological index related to correlativity of the baroreflex system was increased significantly with the repeat count of the experiment. The comparison between the physiological index and the questionnaire on psychological state has suggested that this fact was caused by a decrease in not only stress or anxiety to the experiment but also a decrease in concentration or a reduction of interests in the video image.
