Despite this evidence, imagery training of movements combined with conventional physiotherapy of the hand has been reported in few structured clinical trials including subacute to chronic stroke patients and they demonstrated a greater improvement of hand function with the additional mental practice (Braun et al., 2006; Page et al., 2007; Malouin et al., 2008; Simmons et al., 2008; Verbunt et al., 2008). Up to now, no definite conclusions can be drawn, except that further research using a clear definition of mental practice content and standard outcome measurements are needed. As for the first point, it follows from the definition of MI that because of its concealed nature, a subject may surreptitiously use alternative cognitive strategies that, if not screened for, could confound investigations and produce conflicting results. Because the aim of MI is to activate the motor networks, it is crucial that subjects perform the mental task from the first person perspective (so called kinesthetic MI), in contrast to third person perspective or visual imagery (Decety and Grezes, 1999; Neuper et al., 2005). In this regard, a recent fMRI study on MI (Guillot et al., 2008) has looked at this issue by assessing subjects’ imagery abilities using well-established psychological, chronometric, and new physiological measures from the autonomic nervous system. The results suggest that visual and kinesthetic imagery are mediated through separate neural systems, which contribute differently during processes of motor learning and neurological rehabilitation.