Electroencephalographic Interbrain Synchronization in Children with Disabilities, their Parents, and Neurologic Music Therapists.

As with typically developing children, children with cerebral palsy (CP) and autism spectrum disorder (ASD) develop important socio-emotional rapport with their parents and healthcare providers. However, the neural mechanisms underlying these relationships have less studied. By simultaneously measuring the brain activity of multiple individuals, interbrain synchronization could serve as a neurophysiological marker of social-emotional responses. Music evokes emotional and physiological responses and enhances social cohesion. These characteristics of music have fostered its deployment as a therapeutic medium in clinical settings. Therefore, this study investigated two aspects of interbrain synchronization, namely its phase and directionality, in child-parent (CP) and child-therapist (CT) dyads during music and storytelling session (as a comparison). A total of 17 participants (7 CP or ASD children [aged 12-18 years], their parents, and 3 neurologic music therapists) completed this study, comprising 7 CP and 7 CT dyads. Each music therapist worked with two or three children. We found that session type, dyadic relationship, frequency-band, and brain-region were significantly related to the degree of interbrain synchronization and its directionality. Particularly, music sessions and CP dyads were associated with higher interbrain synchronization and stronger directionality. Delta (0.5-4 Hz) range showed the highest PLV in both CP and CT dyads in frontal brain regions. It appears that synchronization is directed predominantly from parent to child, i.e. parents and music therapists' brain activity tended to influence a child's. Our findings encourage further research into neural synchrony in children with disabilities, especially in musical contexts, and its implications for social and emotional development.