Characterizing functional brain networks and emotional centers based on Rasa theory of Indian aesthetics

In Indian history of arts, Rasas are the aesthetics associated with any auditory, visual, literary or musical piece of art that evokes highly orchestrated emotional states. In this work, we study the functional response of the brain to movie clippings meant to evoke the Rasas through network analysis. We extract functional brain networks using coherence measures on EEG recordings of film clips from popular Indian Bollywood movies representing nine Rasas in the Indian Natyasastra. Structural and functional network measures were computed for these brain networks, averaging over a range of significant edge weights, in different brainwave frequency bands. We identify segregation of neuronal wiring in the brain into modules using a community detection algorithm. Further, using mutual information measure, we compare and contrast the modular organizations of brain network corresponding to different Rasas. Hubs identified using centrality measure reveal the network nodes that are central to information propagation across all Rasas. We also observe that the functional connectivity is suppressed when high-frequency waves such as beta and gamma are dominant in the brain. The significant links causing differences between the Rasa pairs are extracted statistically.