Monday, June 15, 2009

 

On the Origins of Pain and Consciousness

(Sorry. I know that's a lofty blog post title.)

When my father was in the ICU unit last year, and we were informed that he was now medically classified as "brain dead" with little to no hope of recovery, it wasn't difficult for us to decide to remove his respirator. My father and I had had several conversations about the conditions under which he wanted to live or not (and you might have these convos with your family if you have not already). And so while I didn't exactly enjoy that night in the hospital, I did go through it knowing that I was complying with his wishes.

Note, though, that I said my father was "now medically classified as brain dead." Our doctor, in other words, was not completely convinced that this was the case. He was a skeptic. Skepticism is sometimes good.

A tiny detail from that evening: the excellent ICU doctor (if only the ER doctor from the night before had been half-way as decent, my father might still be alive today), made a point of telling me that he would administer anesthesia to my father before we removed the tube so there would be no chance of pain and suffering. While I remember this comment, its significance mostly passed me by at the time. And then, I read this utterly fascinating article in the New York Times by writer Annie Murphy Paul.

Many noted that if Merker is correct, it could alter our understanding of how normal brains work and could change our treatment of those who are now believed to be insensible to pain because of an absent or damaged cortex. For example, the decision to end the life of a patient in a persistent vegetative state might be carried out with a fast-acting drug, suggested Marshall Devor, a biologist at the Center for Research on Pain at Hebrew University in Jerusalem.


A skeptic might say that I was trying to rationalize my grief--and that's fine. I can take that. However, when my father was in the hospital, and even though he never regained consciousness after I arrived, I saw evidence that he knew I was there, and that on some level he acknowledged me and all that I had to say, and that he was then able to pass peacefully. It's personal--I won't go into detail. But I was in awe, and I left the hospital that evening completely awe-stricken and confused by how we exit life. There is a great deal we do not know, and poets and writers sense these great transitions and write about them. One day perhaps science will catch up. But it's unclear that just because the cerebral cortex is damaged, the brain no longer functions and that a person is completely "gone."

In the quote above, Paul is referencing hydranencephaly, a very rare condition in which babies are born mostly with fluid in their cerebral hemispheres. To put it somewhat simply, they don't have a cerebral cortex, the part of the brain with we associate with memory and consciousness. And yet, Paul says, children with this condition (most don't live for long) have been observed laughing and responding to stimuli.

Merker included his observations of these children in an article, published last year in the journal Behavioral and Brain Sciences, proposing that the brain stem is capable of supporting a preliminary kind of awareness on its own. “The tacit consensus concerning the cerebral cortex as the ‘organ of consciousness,’ ” Merker wrote, may “have been reached prematurely, and may in fact be seriously in error.”


There are political implications for a conclusion like this; who can forget the long, drawn out debate surrounding Terri Schiavo? And then of course, there is the issue of abortion, and the point at which a fetus becomes conscious and capable of feeling pain. Paul spends most of her time discussing the complexity surrounding this question in her article. Since I read her piece on a day when I was remembering my father's passing, it was humbling to think about the way in which minds leave the earth . . . and the way in which they enter. When are we conscious? When do we become . . . us?

The article opens with a startling story; newborn babies requiring operations were once not given anesthesia. The risks of medicating these infants was seen as greater than the benefits. It was a sensitive doctor, Kanwaljeet Anand, who suggested the mortality rate of these babies might decline if they were given anesthesia, and indeed it did--from 25% to less 10%. Babies feel pain. It is suggested that they might even remember pain.

But, it's hard to prove.

“Pain perception probably does not function before the third trimester,” concluded Rosen, the review’s senior author. The capacity to feel pain, he proposed, emerges around 29 to 30 weeks gestational age, or about two and a half months before a full-term baby is born. Before that time, he asserted, the fetus’s higher pain pathways are not yet fully developed and functional.


Concomitant with when a baby or fetus does or does not feel pain, is the question of when it becomes conscious. The two may well be entwined. Paul writes:

IN FACT, “THERE may not be a single moment when consciousness, or the potential to experience pain, is turned on,” Nicholas Fisk wrote with Vivette Glover, a colleague at Imperial College, in a volume on early pain edited by Anand. “It may come on gradually, like a dimmer switch.” It appears that this slow dawning begins in the womb and continues even after birth. So where do we draw the line? When does a release of stress hormones turn into a grimace of genuine pain?


I am looking forward to the publication of Paul's book when it is ready. If the article is anything to go by, she will examine all these questions with great care. I read her article not at all as a political statement, but as the product of a genuinely curious mind, trying to understand the most profound questions. And I think that anyone contemplating--as I wrote earlier--how we leave the world and how we come into it, will find the article fascinating, if a little disturbing. But complicated things that are about the human soul aren't necessarily meant to be easy, and I think we do ourselves a disservice if we don't really wrestle with the implications of our increasingly awesome scientific and technological powers.

Comments:
Excellent post, Marie! These are really important questions, and it's so nice to see someone grapple with them honestly, without a political agenda. Condolences, again, on your father's passing.
 
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