Effect of motion smoothness on brain activity while observing a dance: An fMRI study using a humanoid robot

Abstract

Motion smoothness is critical in transmitting implicit information of body action, such as aesthetic qualities in dance performances. We expected that the perception of motion smoothness would be characterized by great intersubject variability deriving from differences in personal backgrounds and attitudes toward expressive body actions. We used functional magnetic resonance imaging and a humanoid robot to investigate the effects of the motion smoothness of expressive body actions and the intersubject variability due to personal attitudes on perceptions during dance observation. The effect of motion smoothness was analyzed by both conventional subtraction analysis and functional connectivity analyses that detect cortical networks reflecting intersubject variability. The results showed that the cortical networks of motion- and body-sensitive visual areas showed increases in activity in areas corresponding with motion smoothness, but the intersubject variability of personal attitudes toward art did not influence these active areas. In contrast, activation of cortical networks, including the parieto-frontal network, has large intersubject variability, and this variability is associated with personal attitudes about the consciousness of art. Thus, our results suggest that activity in the cortical network involved in understanding action is influenced by personal attitudes about the consciousness of art during observations of expressive body actions.

Keywords:

• Functional magnetic resonance imaging (fMRI)
• Motion smoothness
• Intersubject variability
• Dance
• Parieto-frontal network

Acknowledgements

This study was performed at Department of Functional Brain Imaging, IDAC, Tohoku University, Japan. We gratefully thank Yoshihiro Kuroki and Tomohisa Moridaira for their contribution to preparation of the experiment and helpful discussion. This research was supported by JST/RISTEX, R&D promotion scheme for regional proposals promoted by TAO, JST/CREST, and Research Center for Language, Brain and Cognition, Graduate School of International Cultural Studies, Tohoku University.