###### Abstract
As a result, methodologies with individualized training protocols, that suit each patient's condition, are needed. With these considerations, incorporating neuroimaging techniques into MI practice could set foundations for the study of patient-specific MI-induced mental patterns, enabling the identification of relevant features for MI neurofeedback training (NFBT). In NFBT, the brain activity is recorded and relevant features related to the task under consideration (in this case, MI) are fed back to the user, who must develop strategies to learn to modulate them in real-time to achieve pre-defined goals [16]. Therefore, this type of therapy could deepen the engagement and recruitment of the central nervous system into rehabilitation protocols. Although NFBT is generally controversial in the scientific literature, applications specifically involving MI tasks are usually more substantiated [17; 18; 19]. Indeed, several studies have suggested that both healthy and neurologically damaged subjects could modulate their brain activity associated with MI in real-time, provided that appropriate training conditions are met, indicating: enhanced hemodynamic activity in the trained cortical areas [20; 21; 22], as well as in the contralateral motor cortex to the trained limbs [23], and improved hand dexterity [20; 21]; larger lateralization of motor imagery cortical activity, recorded through electroencephalography (EEG), over the training time course [24]; and higher EEG activation during MI following NFBT [20]. The successful application of MI-NFBT requires the correct identification of relevant features that relate to MI-generated mental patterns to their appropriate feedback to subjects. Nonetheless, to the best of our knowledge, there is only a limited number of this type of studies involving children with CP. Furthermore, given the aforementioned difficulties concerning their MI capability, it becomes essential to initially tackle the problem by exploring whether such patients can exhibit the expected response for MI in the form of contralateral event-related desynchronizations (ERDs), usually established as the \"gold standard\" for the MI response that can be detected with EEG [25; 26; 27], and frequently the measure of interest in EEG-NFBT MI-based applications (e.g., [23; 28; 29]). In this regard, in 2017, [PERSON] and colleagues proposed a rehabilitation paradigm for children with CP based on virtual-reality (VR) and MI detection with EEG [30]. The authors proposed a VR-MI intervention in which children interacted with a gamified interface through virtual reality glasses: patients navigated the virtual environment in first-person and should overcome the proposed challenges through gate onset MI. After undergoing two initial calibration (sham) sessions aimed at identifying each subject's optimal EEG features, which were based on the ERD response, participants took genuine control of the interface and were able to achieve the experiment's goals. Despite the small number of children in this study (three children with CP), its results provided strong evidences for the feasibility of designing MI-based systems for children with CP. Results also reinforced the concept that each MI-related mental patterns are subject-specific and should be considered as such. More recently, another study assessed the effects of associating MI with traditional physical therapy on upper limbs rehabilitation in children with CP. The authors measured patients' performance through the Assessing Hand Assessment (AHA) pre- and post-intervention, and at a follow-up session. Participants were divided into a control group, which only received traditional physical therapy, and an experimental group, that received both the traditional and MI interventions. Overall, the authors reported that improvements in the AHA scores were larger for the experimental group, which were also mainted at the follow-up period [31].