## 4 Discussion
While during movement, processes resulting in motor initiation are intended, during movement imagination, these processes need to be inhibited. FMRI studies demonstrated a suppressed connectivity to M1 during movement imagination, while this connectivity was enhanced during movement execution [52; 53]. In our study, sportive patients show a higher connectivity to the left M1 in the alpha band compared to the non-sorptive patients, aligning their pattern with that found in healthy controls--this might represent an effective suppression of M1. One possible explanation for this might be that sportive patients regularly train their movement imagination skills, especially wheelchair dancers. They have to prepare, memorize and practice a choreography composed of complex movements that need to be arranged with the steps of the dance partner. Hence, imagining complex movements while suppressing their execution might be more present in the sportive patient group than in the other groups. Furthermore, the increased suppression of M1 might compensate the elevated cortical excitability [46; 47; 48] to avoid unwanted movements. In the beta band, the data showed a higher connectivity toward the left M1 in the sportive compared to non-sorptive patients during movement. The higher frequency indicated an enhancement in M1 activity that might be modulated by sports after SCI, resulting in a physiological level. Furthermore, it is of interest that in our data, the M1 in the role as connectivity sink was located only in the left hemisphere. Functional MRI studies revealed that the left hemisphere possesses greater intrahemispheric local connections than the right one, particularly in brain areas associated with language and fine motor coordination [54]. In contrast, the right hemisphere was reported to show more interhemispheric connections than the left counterpart [55; 56]. In our study, intrahemispheric connections over the left hemisphere were stronger in sportive patients as compared to non-sorptive patients, while the difference was smaller and of opposite direction in healthy participants; hence, the increased intrahemispheric connectivity might be influenced by the combination of exercise and implications of the SCI. Still, it has to be kept in mind that the role of M1 during movement imagination is not yet clear. [PERSON] and colleagues reviewed the literature on this topic and reported that out of 122 experiments that were published, only 22 observed activity of M1 during imagination of movement [57]. More research is needed to clarify the role of M1 during imagination and its task as source and sink of information flow in different frequency bands. In addition to what we observed in M1, the connectivity toward the right PPC showed different patterns between the groups. In the alpha band, the non-sorptive patients had a higher connectivity compared to all of the other groups. In former studies, the PPC played an important role in restraining movement imagination [58], the integration of spatial orientation [59], and the concept of the \"body schema\", i.e., the bodily posture and the position of limbs [60]. It receives input from brain areas including motor, somatosensory, visual, auditory, cingulate, and prefrontal cortices, and integrates proprioceptive and vestibular signals from subcortical areas. Hence, the PPC serves higher-order functions [61]. In an EEG study, [PERSON] and colleagues recorded a lower connectivity in the functional sensorimotor network in patients with SCI [18]. Due to the deafferentation and an impaired exchange of signals between the central and peripheral nervous system, the body schema might be modified in patients with SCI. This could interrelate to the increased suppression of the right PPC as reflected by increased alpha band connectivity in non-sorptive patients.