## 3 Results
### Individual Results--Study of the Networks' Topology through Graph Metrics  
Despite the aforementioned results for general trends at the group level, each brain is unique and, especially in the case of neurologically damaged patients, brain plasticity and functional reorganization mechanisms can be especially important to guide intervention protocols [48]. Therefore, intra-subject analyses were also performed, to explore possible subject-specific effects of the AO+MI-VR intervention. The following results were obtained setting the thresholds values to the most restrictive possibility explored in this study; that is: \((\rho,r)=(0.30,0.75)\). For all metrics, variations were simply taken as the difference between their values at the corresponding nodes between the post- and pre-intervention periods. Hence, positive variations indicate increases in the metric following the AO+MI-VR session, and vice versa. We emphasize that these analyses are highly exploratory. Nevertheless, we attempted to extract common patterns, whenever possible.  
**Degree:** Figure 5 shows results for the degree for each subject (rows), and for all frequency bands (columns). The circles' radii around each electrode site directly relates to the magnitude of the metric's change, as also represented by the colors scale.  
The main sites for degree changes (Figure 5) are predominantly on the areas indicated by the group's graph--i.e., frontal and parietal sites. Variations on the C-labeled electrodes (except for S03 in the \(\alpha\) range and S01 in \(\beta_{2}\) and \(\gamma\)) could also be observed, although to a lesser extent.  
**Clustering Coefficient:** Figure 6 displays results for the CC. Empty plots should be interpreted as not containing statistically significant variations. Overall, similarly than for the degree (Figure 5), alterations in the CC were more often found over frontal and parietal nodes. However, in this case, most prominent variations were especially localized closer to the scalp's midline--which is especially true for S01. This means that, even though the total number of connections generally varies all over the scalp (Figure 5), alterations in the CC are, at least to some extent, more restricted to sites closer to the scalp's midline. Regardless, as with the degree, the type of change (i.e., increase or decrease) is highly subject-dependent.  
**Node path length:** Even though alterations in the degree and clustering coefficient were observed, no statistical significant changes were found for the node path length with our methodology.  
**Betweenness Centrality:** Figure 7 shows results for the BC. Differently than for the other metrics, and with only a few exceptions (namely, S05 in the \(\alpha\) range), the BC generally displayed, most noticeably, decreases. In addition, nodes with increased BC overall present a smaller magnitude (which can be seen through the smaller circle's radii). Once more, results are largely subject-specific and emphasize frontal and, parietal nodes, with less stress on central electrodes.  
Figure 5: Degree variations between pre- and post-intervention for all subjects and frequency bands; \(r=0.75\) and \(\rho=0.30\). Plotted radii are subject-specific. Only statistically significant variations are shown (\(p<0.00002\); Wilcoxon test).  
Figure 6: CC variations between pre- and post-intervention for all subjects and frequency bands; \(r\) = 0.75 and \(\rho\) = 0.30. Plotted radii are subject-specific. Only statistically significant variations are shown (\(p\) < 0.00002; Wilcoxon test).