Evaluation of Kinesthetic/Visual Motor Imagery of Dorsiflexion of the Right Ankle Joint via Event-Related Desynchronization/Synchronization

Motor imagery, which is an image of movement without actual motion, is divided into kinesthetic or visual motor imagery (K/VMI). KMI is known to show brain activities that are closer to those associated with actual movement than VMI. Therefore, it is suggested that KMI is useful for rehabilitation of patients with stroke hemiplegia. The purpose of this study was to evaluate K/VMI using a questionnaire and an event-related desynchronization/synchronization (ERD/S). Eight healthy males (21 to 26 years old) were asked to perform K/VMI or movement execution/observation (ME/O) of the dorsiflexion of the right ankle joint and non-motor imagery (NMI) as tasks. Time-frequency analysis of electroencephalograms of the task was conducted via short-time Fourier transformation. Then, ERD/S (the change rate of the power spectral density compared to the resting state) was calculated. Furthermore, spatiotemporal analysis of ERD/S was performed in the alpha (10 to 13 Hz) and beta (13 to 35 Hz) bands. As a result, it is suggested that K/VMI evaluation using a questionnaire could be achieved from spatiotemporal ERD/S by noting the differences in KMI vs. VMI, KMI vs. ME, and VMI vs. MO.