Funding: the study was part of the state-funded project RFMEFI60519X0186 on the Development of a BCI-based hand exoskeleton with biological feedback for the rehabilitation of children with cerebral palsy. The study was supported by the Ministry of Science and Higher Education of the Russian Federation.

Author contribution: Larina NV, Korsunskaya LL, Vlasenko SV — data acquisition, manuscript preparation; Nacharova MA, Pavlenko VB — data analysis, manuscript preparation.

Compliance with ethical standards: the study was approved by the Ethics Committee of Vernadsky Crimean Federal University (Protocol № 53 dated December 06, 2018). Informed consent was obtained from the patients or their legal representatives.