Thursday, February 4, 2010

Knock, knock. Are you there?

There's a sobering, if not scary, story in the Feb 3 issue of the New England Journal of Medicine. British and Belgian physicians have been able to use brain scans to communicate with patients thought to be in a vegetative state. By monitoring brain activity, and asking the subjects to imagine one kind of activity if the answer to a question was 'yes' and to imagine another type of activity if the answer was 'no', they were clearly able to get responses from a high fraction of subjects (conscious controls were used as comparisons).

As usual, the hyperbolizing science press, in this case our favorite, the BBC, said that scans "unlocked" vegetative patients. From the headine, one envisioned them getting up and going out for a spot of tennis. But there's no such thing. What the scans did was allow researchers to communicate with these suffering people. They are still 'locked' from normal activity, brain or physical. Too bad, since these are important and interesting findings that didn't need the exaggeration treatment that journalists simply can't refrain from.

This has obvious implications for many aspects of supposed vegetative states, not least being that associated with decisions to withdraw care and allow the patient to die. But some deeper questions might also be asked, and they have to do with how these results are being interpreted. The key question is whether these individuals were conscious or not.

Given the patients' clear responsiveness to decision-making tasks (answering questions), one might assume that this implied consciousness. Indeed one commenter quoted in the NY Times report on this story says it opens new a new window into human consciousness. But that may not be so. Many experiments on humans who have had surgery that impaired one of their hemispheres, or separated their two hemispheres, have shown that rational, responsive, decision-making capability exists independent of consciousness. Other recent work shows that conscious awareness may monitor, but comes split seconds after decisions are made by the brain. In other words, brains can think without being conscious. Apparently the NEJM ran a commentary by a Dr Ropper, who does not claim this has to do with consciousness--'identity' is the word he used, which seems to us to reflect a proper reserve.
The fact that brains can think without being 'conscious' is interesting and relates not just to the question of what consciousness actually is and how we can ever know that, but also what sort of consciousness other organisms, ranging from apes to ants, may have. They all clearly make decisions and act rationally. They can solve problems, coordinate action with others, and evaluate their circumstances. And they respond. But are they 'conscious'? Can they be asked if they wish to life or die?

Who knows. But the responsiveness of people in vegetative states raises this question along with the ethical questions about euthanasia and so on. For example, suppose it could be shown that these unfortunate people are not conscious, but that their unconscious brains are functioning. Should we ask those partially aware brains if they want to live or die?


no2 monitor said...

This is astonishing! Perhaps this can really lead to some cure in the future. I still believe that miracles can still happen. We don't know what our future holds, but we know who holds our future. Let us give these patients and their families some hope to hold on.

Holly Dunsworth said...

Their unconscious brains are functioning or else they'd be dead. Right? So this is fascinating news today but what's significant is not that it's surprising (since unresponsive yet alive people still have all kinds of processes still running all through their bodies, otherwise they'd be dead), but what's significant is, I think, exactly what you described... it gives us a new way to think about consciousness and cognition across species. It gets us closer to understanding which of our behaviors (that result from human consciousness and cognition) are the same in other species or not! I can't help but think of B.F. Skinner's stimulus-response theory with these findings. Except, if these results do imply that Skinnerian processes are at work, that does not mean that they work like they do in humans in other species. So even if we are just machines, that doesn't mean we're toad machines or dung beetle machines.

Holly Dunsworth said...

Also, I couldn't help but wonder if you get the same brain scan results when you communicate with infants younger than the age of language acquisition.

Holly Dunsworth said...

Sorry about the confusion about brain dead vs. vegetative state (unresponsive, alive, dead, etc) that was implied in my first post. I still don't understand what these medical categories entail.

Michael said...

I don't think we need to decide what consciousness is to figure out whether these patients are conscious or not. This is obvious in the normal case - I don't need to figure out what consciousness is to know that you are conscious.

All we'd need to do is see if they can respond to a bunch of questions, the same way conscious people do. If they can comment on their own condition, express beliefs and desires (even just with yes/no answers) then it would be wrong-headed to decide that they are not conscious.

John said...

I need to see the experimental protocols; in the absence of same, we are all just speculating nonsense. Did they ask ground truth questions, for example, to discriminate between brain states (e.g. is you name ``Fred''?, do you have a dog?, are you an alien from Zortar?, do you have 11 ambulatory limbs?). I don't know (details are scarce), but one needs to know, otherwise, as usual, we are just fooling ourselves. Secondarily, I am concerned about the pooling of responses alleged in these reports: were these patterns observed in all, or just a few? There may be the possibility of a few functional humans caught up in our overly-regulated medical world. I do doubt, however, that it extends to more than a few. No question, if they exist at all, we should find, and help them re-conect. These reports, however, leave me skeptical.

Anyway, early times yet

Ken Weiss said...

Early times yet, indeed. I have not seen the actual paper yet myself, but they seem to have answered some of your questions (getting person-specific responses).

As to consciousness, our point was that what we call consciousness is apparently not the only kind of self-awareness that we have. As I understand the split-brain experiments, self-aware responsiveness occurs without conscious awareness in the usual sense, and the latter also has, we've read, occurs a very short time after decisions have been made by the brain.

But of course there's much speculation in all of this.

Michael said...

I think the split brain experiments are open to a number of interpretations regarding their implications for consciousness. One such interpretation is that once the communication between the parts of the brain is interrupted, each (to a degree) has its own consciousness. The confabulation and other phenomena that we see can be explained via such an interpretation.

But I agree with your general point - that there are degrees and types of self-awareness.

I do think there is something confused in talking about "brains thinking". As a commenter on my blog said it "makes about as much (or as little) sense as talking about hepatic decision making processes in the lobes of my liver."

Ken Weiss said...

I'd say the split-brain experiments, which I realize are open to various interpretations, show that the normal, verbally conscious half (usually the left, I think) reports normal ego experiences as before the surgery to separate the halves. But the right side, which can still solve 'thinking' problems, has no such awareness that has been found or at least the left side doesn't know what the right side is up to. At least, that's how I've understood the gist of the results.

At least, I think the debate about 'consciousness' is about the self-aware, reporting, cogitating 'ego' function that we experience, and I think evidence shows we do a lot of problem-solving that doesn't involve that (autonomic functions are probably another example).

But I agree about your final comment. I'm abashed to confess I don't know your blog, but if you post its address here, readers of evodevoeco can learn of it, if they don't already know it.