ИСТИНА

The mirror therapy (MT) and the action observation (AO) are widely used post-stroke rehabilitation methods. Both observation of movements and the mirror feedback (MF) lead to the activation of motor and sensorimotor areas. In EEG studies, the effect of AO and MF is manifested by sensorimotor rhythms amplitude decrease (event-related desynchronization, ERD). Besides ERD, the post-movement beta rebound (PMBR) may be indicative for the cortex activity. PMBR is associated with motor cortex inhibition after movement termination. Despite the popularity of AO and MT as rehabilitation methods, differences in the mechanisms of their impact on the cortex remain unknown. The EEG was used to study the beta-rhythms dynamic of 25 healthy participants during AO and mirror illusion. The mirror was placed along the sagittal plane and reflection of the moving right-hand provided the illusion of bimanual movements. We used the functional electrical stimulation (FES) to perform passive movements (similar to the voluntary) . Using common localizer task, we constructed sensitive spatial filters to identify the sources of sensorimotor spectral events: beta ERD, post-movement beta-rebound. We found a significant increase in beta-ERD during AO in both hemispheres. At the same time, MF did not lead to beta-ERD changes. The spectral power in PMBR sources decreased in MF conditions. Our results suggest that AO and MF lead to the activation of different neural networks. ERD reflects the sensorimotor cortex activity, but MF affects premotor and motor cortices (that reflects in PMBR decrease). We found that the effects of MF with active and withj FES-induced movements are similar. This allows us to offer MT for people with the bilateral paresis, where movement can be triggered by FES. Our findings confirm that despite the fact that both AO and MF activate sensorimotor and motor area, they do it in different ways.