Persistent Vegetative State (PVS) is a diagnosis often marked by controversy. Until a few weeks ago, it was presumed that people in a PVS were not conscious of their surrounding, but recent research suggests that people in a PVS can demonstrate willful intent:
To determine whether the patient might exhibit evidence of conscious awareness, they presented her with spoken instructions to imagine herself playing a game of tennis, and to think of herself visiting all the rooms of her house, starting from the front door.
Scans taken when she was asked to play an imaginary game of tennis revealed significant activity in the supplementary motor area, whereas imaging performed during the imaginary house tour lit up sections of the parahippocampal gyrus, the posterior parietal cortex, and the lateral premotor cortex, regions mapped to visuospatial tasks. Again, the responses were similar to those seem with healthy volunteers asked to perform the same tasks.
The investigators asserted that “her decision to cooperate with the authors by imagining particular tasks when asked to do so represents a clear act of intention, which confirmed beyond any doubt that she was consciously aware of herself and her surroundings.”