Wednesday, August 24, 2005

New Meta-Study on Fetal Pain

Ok, I've dropped the three things I was doing all at the same time to look at the new article in JAMA on fetal sentience. The NYT write up of the JAMA article, which puts it in the context of recent legislation demanding that abortion providers give anesthesia to the fetus, is here.

I've got to run home soon to look after the kids, so I'm just going to live-blog my reaction to the article.

~5:10: Looking at references. "Cool. They looked at a lot of the same research I looked at when I studied the issue. This means that I wasn't completely misguided when I tried to do this for myself."

~5:15: Reading the introduction and definition of pain. "Ok, they are using the IASP definition of pain, which I think I endorsed when I was looking at this issue. Oh but wait. They are setting things up so that the thalamocortical connections are a necessary condition for sentience. I can see already where this is heading."

~5:19: "The are explaining some basic stuff in this article. They know they are writing for a popular audience."

5:23: "They began by listing the search criteria they used for their meta-level study, but the bulk of the article so far reviews studies of thalamocortical connections which wouldn't have shown up in their first search for articles on fetal pain. How much of this business of listing your search criteria in your meta-level study is really true to the thought process that went into the paper? Is this another case where the paper presents a logic of justification quite different than the logic of discovery?"

5:32: I stopped looking at the article, and spaced out for a bit, a move sparked by their diagram on page 348. The diagram there contrasts spinal reflect circuits with circuits that go through the thalamus to the cortex. The latter we are supposed to infer, are real pain, while the former are just reflex. My recollection from reading Valarie Hardcastle's The Myth of Pain, though, is that there are two kinds of circuits that go all the way to the brain, the C-fibers and the delta-fibers. The C-fibers hook up to the thalamocortical conction in the diagram that Lee et al. have, but the delta fibers don't. Really the delta fibers aren't on this diagram at all.

But the delta fibers are important. They are a pain system we share with lower animals. The c-fiber system is only in the great apes. (again, I'm trying to recall hardcastle here.)

Ok, I'm all ready to assert a thesis: there are at least two kinds of pain, ape pain and dog pain. This article only concerns ape pain.

5:35: call from molly. I'm not going to finish this article before 6.

5:43: Page 940 has a lot of summaries of articles that inferred fetal pain from some circumstantial evidence, like behavior, cerebral blood flow and EEG patterns. Each gets a one sentence reply. The pattern of argument seems to be "This is a tenuous inference, whereas we have simply defined pain as requiring thalamocortical connections, so our evidence is stronger." I'm not thinking of this article as definitive, merely a salvo in an existing argument.

5:51: Reading the conclusion. When I taught this issue in my medical ethics class, I put in my PowerPoint that the "major pain circuit" was online at 29 weeks. The JAMA article reaches the same conclusion, based basically on a more detailed review of the same evidence. The one point where the authors and I differ is on the importance and possibility of other pain circuits. Of course, they are doctors writing in JAMA, and I am a philosopher blogging.

No comments: