*1.1.2 Motor imagery (MI)*

MI is imagining a motor action without any efferent information to neuromuscular system. Thoughts and actions are intimately linked. A confirmation of this prediction is found in the spatial patterning of activated cortical areas seen with functional brain imaging techniques such as PET and fMRI [9]. MI is widespread in BCI systems because it has naturally occurred discriminative properties and also because signal acquisition is not expensive [8]. It is widely used in sport training as mental practice of action, neurological rehabilitation, and has also been employed as a research paradigm in cognitive neuroscience and cognitive psychology to investigate the content and the structure of covert processes (i.e., unconscious) that precede the execution of action. The effectiveness of motor imagery has been demonstrated in musicians. There have also been conducted multiple studies on its uses in neurological rehabilitation in patients after stroke [10].
