Assessment of the Impressions of Robot Bodily Expressions using Electroencephalogram Measurement of Brain Activity

Recently, robotics research has focused on issues surrounding the interaction modalities with robots, how these robots should look like and how their behavior should adapt while interacting with humans. It is believed that in the near future robots will be more prevalent around us. Thus it is important to understand accurately our reactions and dispositions toward robots in different circumstances (Nomura et al., 2006). Moreover, the robot’s correct production and perception of social cues is also important. Humans have developed advanced skills in interpreting the intentions and the bodily expressions of other human beings. If similar skills can be acquired by robots, it would allow them to generate behaviors that are familiar to us and thus increase their chances of being accepted as partners in our daily lives. The expressiveness of a gesture is of great importance during an interaction process. We are often required to give special attention to these signs in order to keep track of the interaction. Humans have learned to adapt their behavior and to react to positive and negative bodily expressions (Bartenieff & Lewis, 1980). Although there has been remarkable work on the design issues of sociable robots (Breazeal, 2002) and affective autonomous machines (Norman et al., 2003), there has not been much work on investigating the real impact of robot bodily expressions on the human user in the context of human-robot interaction. Knowing the effect of a generated gesture, a robot can select more accurately the most appropriate action to take in a given situation. Besides, computer-animated characters have been used to evaluate human perception of the significance of gestures. However, animated characters and embodied ones should be treated differently since the latter are tangible entities (Shinozawa et al., 2005). In this article we report a study on the relation between bodily expressions and their impacts on the observer. We also attempt to understand the effect that expressions have on the observer’s brain activity. Its sensitivity to bodily expressions can be used during an interaction task since the brain is the source of every cognitive and emotional effort.