As much as I regret bringing up anything that will revive the Terri Schiavo debate, and as skeptical as I am about how much brain-scan technologies in their current state actually tell us about the human mind as we experience it as living conscious beings, this is still worth noting and contemplating: a 23-year-old British woman in a persistent vegetative state apparently is understanding and reacting in her brain to verbal directions, by the standard methods neuroscientists interpret brain activity as equivalent to "understanding and reacting."
New ethical dilemma: if this sort of mental activity, if mental activity it is, exists but can't be manifest in communication or action, how much ethical value should it have in the debate over who is "truly human" or "deserving of life" that requires the use of medical care methods that others are paying for? Does it change any existing judgements as to what sort of life is "really" worth living for those contemplating Living Wills, or for those who interpret them? Will people now want to specify, "use extraordinary means to keep me alive as long as MRIs indicate I'm understanding what people say?" Or, given that none of us beforehand can know experientially what it is like to be in a persistent vegetative state with or without such MRI reactions, does this give us any more useful data in making decisions now about what we are going to, or would, really want to do about living or dying in such a state?