## 3 Results
### Multi-Domain Assessment Results
#### 3.2.3 EEG Analysis  
The EEG analysis showed that, on average, a desynchronization was recognizable in primary motor cortex bilaterally (electrodes: C3 and C4), in both the pre- and post-rehabilitation phases as depicted in Figure 5. However, at T0, the ERD appear to be mostly occurring in the beta band for  
Figure 4: Patients’ spatial synergies, extracted at T0 and T1, are depicted in the first and second columns, respectively. The corresponding temporal components are depicted in the fourth and fifth row. For each T0/T1 correspondent couple of motor modules, similarity on spatial synergies and on temporal components is reported in column 3 and column 6, respectively.  
the ipsilateral hemisphere, while temporally limited to only part of the movement execution in the contralateral. Conversely, at T1, the desynchronization spreads to all frequencies (alpha and beta) and to the overall movement execution in both ipsilateral and contralateral areas.  
In order to provide a comprehensive picture of the overall brain activity, the RP values were computed for all electrodes and averaged out on the five patients by mirroring the results of the task performed with the left hand. The spatial ERD maps, averaged out in 5 times windows, are shown in Figure 6. It can be seen that, despite being spread to most of the scalp, the average desynchronization evolution varies from T0 to T1, especially in alpha. While before treatment the ERD starts after the movement initiation (MOV2, MOV3) and is slightly pronounced, after the rehabilitation it occurs even in the PRE-MOV window. Beta band changes were not noticeable comparing T0 to T1.  
The T0 and T1 distributions of ERDi, ERDc and LC were not significantly different both for alpha and beta bands. Despite this result, a decreasing trend is evident in the alpha band both for the ipsilateral and contralateral hemispheres as shown in Figure 7, meaning that \(\overline{ERDi}(T1)<\overline{ERDi}(T0)\) and \(\overline{ERDc}(T1)<\overline{ERDc}(T0)\), while an average ERD intensification occurred for the contralateral side only in the beta band. In agreement with the previous observations, there is not a clear trend in the alpha-based LC distribution pre-/post-treatment since both ERDi and ERDc decrease, while LC in the beta band moves from negative (T0) to positive (T1) values (ERDc decreases while ERDi seems stable).  
Figure 5: The average maps representing the time-frequency distribution of the ERDi (**A**,**B**) and the ERDc (**C**,**D**) before treatment (T0, **A**–**C**) and after robotic rehabilitation (T1, **B**–**D**) are shown. A color legend, on the right of each scheme, identifies the corresponding ERD intensity. The baseline [\(-4.5\) s, \(-2\) s], the pre-movement [\(-1\) s, \(0\) s] the central part of the movement [\(0.6\) s, \(1.8\) s] and the post-movement [\(2.4\) s, \(3.4\) s] windows along with the alpha [\(8\) Hz–\(13\) Hz] and beta [\(13\) Hz–\(25\) Hz] bands, are delimited by dashed lines perpendicular to the x and y axis, respectively.  
Figure 6: Topographic visualization of the average ERD (arbitrary unit) in five time windows, i.e., before movement initiation (PRE-MOV [\(-\)1, 0 s]), during movement (MOV1 [0, 0.6 s], MOV2 [0.6, 1.8 s], MOV3 [1.8, 2.4 s]) and after the movement termination (POST-MOV [2.4, 3.4 s]). The maps of patients performing the movement by means of the left hand (impaired one) were mirrored.  
Figure 7: Distributions of ERDi, ERDc and LC, before (T0) and after (T1) the robotic rehabilitation, are shown for the alpha (**A**) and beta (**B**) bands. The central line indicates the median, while the lower and upper extremities of the boxes represent the 25 th and 75 th percentiles, respectively. The whiskers comprise all the data points distribution except the outliers, which are plotted separately using the ‘+’ mark.