Event-related desynchronization and synchronization (ERD/S) and
movement-related cortical potential (MRCP) play an important role in
brain-computer interfaces (BCI) for lower limb rehabilitation, particularly in
standing and sitting. However, little is known about the differences in the
cortical activation between standing and sitting, especially how the brain's
intention modulates the pre-movement sensorimotor rhythm as they do for
switching movements. In this study, we aim to investigate the decoding of
continuous EEG rhythms during action observation (AO), motor imagery (MI), and
motor execution (ME) for the actions of standing and sitting. We developed a
behavioral task in which participants were instructed to perform both AO and
MI/ME in regard to the transitioning actions of sit-to-stand and stand-to-sit.
Our results demonstrated that the ERD was prominent during AO, whereas ERS was
typical during MI at the alpha band across the sensorimotor area. A combination
of the filter bank common spatial pattern (FBCSP) and support vector machine
(SVM) for classification was used for both offline and classifier testing
analyses. The offline analysis indicated the classification of AO and MI
providing the highest mean accuracy at 82.73±2.54\% in the stand-to-sit
transition. By applying the classifier testing analysis, we demonstrated the
higher performance of decoding neural intentions from the MI paradigm in
comparison to the ME paradigm. These observations led us to the promising
aspect of using our developed tasks based on the integration of both AO and MI
to build future exoskeleton-based rehabilitation systems.Comment: in pres
