ヒューマノイドロボットに対するミラーニューロンシステムの反応

Many types of humanoid robots have been developed recently, and they are mainly<br> designed for social interaction with human beings. The most communicative partners<br> for human beings are other humans. Therefore, to develop successful communicative<br> robots, it is important to know how closely they resemble a human. In the present<br> study, we attempted to evaluate the human likeness of a humanoid robot (Robovie)<br> by using near-infrared spectroscopy (NIRS). Since activity of the human mirror neuron<br> system (MNS) is thought to reflect the perceived human likeness of observed agents,<br>we compared MNS activity during observations of an action performed by a human<br> and the robot. Seven male and ten female participants were included in the study, and<br> eventually, fourteen of them were analyzed. NIRS probes were placed at the bilateral<br> premotor and primary motor areas, which are components of the MNS. Under obser<br>vation conditions, stimuli were presented live or on a video monitor; there were four<br> observation conditions, namely, live-human, live-robot, video-human, and video-robot.<br> After the observation conditions, the participants executed the same action performed<br> by the human agent in the observation conditions by themselves (execution condition).<br> We identified the NIRS channels in which significant activation was induced under both<br> the observation and execution conditions, and used this information to determine the<br> possible regions reflecting MNS activity. We found no significant effect of the agent<br> (human/robot) on MNS activity, and this indicated that MNS response in the motor<br>related area is relatively analogous irrespective of the agent (human/robot). However,<br>the effect of the mode of presentation (live/video) was found in a few channels. Two<br> channels corresponding to the left ventral premotor cortex were activated more strongly<br> in the live condition than in the video condition, particularly when the agent was the<br> human. In contrast, one channel corresponding to the right primary motor cortex was<br> activated more strongly in the video condition than in the live condition only when the<br> agent was the robot. These findings suggest that live presentation of action is necessary<br> to reveal true brain activity in actual situations.