As LiveScience explains, when asked to imagine playing tennis, some patients who couldn’t otherwise move on command did show activity in the part of the brain tied to movement in a way that was similar to how a healthy person’s brain would respond. The researchers describe the portion who did so as a “significant minority.” “If a patient’s ‘awareness’ networks are intact, then we know that they are likely to be aware of what is going on around them,” one of the study authors tells Cambridge News. The researchers note that more work is needed before a viable diagnostic tool can be created. (A man in a vegetative state recently reacted to a Hitchcock movie.)