## 3 Results
In a case study, the exposure of an SCI patient to a very realistic immersive virtual environment combined with auditory and thermal stimuli consistent with the scenario and with tactile vibratory stimuli coherent with the action (walking) has been shown to provide high levels of SoE [15]. Many attempts to provide realism to a BMI experience have been performed by several research groups. For example, it has been proposed that the control of robotic hands with a more human-like shape through MI-BMI may induce higher SoO than controlling robotic hands with the shape of mechanical tweezers [53]. Nevertheless, both conditions seem to induce high scores of SoA that do not differ significantly from each other. Also, in another study in which the MI-BMI task consisted in popping virtual balloons with virtual hands or with virtual blocks, both conditions showed high scores of SoA but did not differ among themselves [20]. In this same study, it was also found that the illusory induction of a sense of movement in one's own hands was greater in the virtual hands' condition than in the virtual blocks' condition. The BMI tasks present in the studies analyzed typically involve training and evaluation phases. Interestingly, these studies tended to adopt realistic conditions in their evaluation phases, but the training phase for the acquisition of sensorimotor activity related to MI typically followed a standard protocol using simplistic arrows and a bar graph as visual feedback [65]. Exceptions to this are the studies by [PERSON] and [PERSON] (2018) and [PERSON] and colleagues (et al., 2022). [PERSON] and [PERSON] (2018) also decided to explore if the introduction of a realistic scenario already in the training phase leads to a higher rate of SoE. However, they concluded that the more realistic experience during the training phase does not seem to significantly affect the SoO and SoA scores during the experience evaluation phase [17]. Meanwhile, [PERSON] and colleagues (et al., 2022) used a highly realistic scenario in the training and evaluation phases to ensure that spinal cord injury patients maintained high levels of engagement throughout the multiple sessions that constituted the experimental protocol [15]. Only four of the twenty studies included some type of haptic stimulus [15; 57; 56; 37]. Three applied the stimulus in the form of vibration while one applied it in the form of electrostimulation. The vibratory feedback was applied in two studies, not intended to replicate the real tactile sensation expected in an action performed, but its application intended to be consistent with the timing of some event in the virtual scene. In the study of [PERSON] et al. (2022), the BMI task allowed an avatar of the subject taking steps. The vibration stimulus matched the moment that the sole of the avatar's foot touched the ground when walking and was delivered to the participant's forearm [15]. Meanwhile, in the study of [PERSON] and colleagues (2019), the vibratory stimulus was applied to the participant's hand and was consistent with triggering a weapon from a spaceship. Both studies reported high levels of SoO and SoA despite the very different conditions tested [57]. Figure 3: Number of studies per type of stimulation. Differences were found for the SoL where the apparatus of [PERSON] et al. (2022) seems to have also induced high levels of SoL. It should be noted, however, that multimodal feedback was used (visual, auditory, and tactile) and the contribution of each modality was not individually assessed. The application of a vibratory stimulus as feedback to mimic the sensation induced by the action if it was truly performed was explored in the study of [PERSON], [PERSON], et al. (2017) [46]. A vibratory stimulus was applied in the right bicep's brachial tendon of the subjects, inducing the proprioceptive illusion of downward extension of the elbow while performing a similar movement with a virtual arm via MI-BMI. This condition was compared with a vibratory stimulus applied over the bone (not inducing a proprioceptive illusion).