2018 年 54 巻 1 号 p. 39-45
As the issue of mental stress in severity, researchers have started to make efforts to give healing through the interaction with robots. Most of robots used in therapy developed for interacting in a state to be held. Therefore, the relative evaluation between the expected weight and the weight sense when holding the robot (hereinafter called “subjective sensory weight”) is likely to affect stress relief effects. In this paper, we examined influences of the subjective sensory weight for stress relief effects. According to the assimilation-contrast theory, in consideration of the adaptation-level varied with the users, we divided participants into the assimilation group and the contrast group and carried out the experiments. Psychological evaluation results showed that the reduction in the depression, the anger and the confusion score in the assimilation group were significantly higher than those in the contrast group. Physiological evaluation results showed that the increase in the percentage of alpha waves in the assimilation group was marginally significantly higher than that in the contrast group. These results suggest that it is necessary for improving stress relief effects by interacting robots to set the weight of the robot which was neither more nor less than users had expected.