Ouch!

This slightly odd article in PLoS Medicine got me to thinking. The point of the study was to try to assess whether the usual signs that an infant is in pain -- which would be, you know, grimacing and crying and stuff -- are necessarily going to happen whenever pain is present. That may seem like a dumb question, but I don't suppose it is. The neurological equipment is still getting hooked up in very young infants and maybe the pain-related reflexes aren't always happening even though the pain already is.

So these people measured blood flow in brain regions normally associated with pain when infants got stuck in the heel for a blood sample. (Don't worry, these were blood samples that the doctors were taking anyway for clinical assessment.) They compared the results of this assessment with scores on a behavioral assessment of pain in premature infants, and they found that sometimes there were signs of pain in the blood-flow data that didn't show up in the facial expression and physiological responses. Now, the authors seem to assume that this means the infants are subjectively experiencing pain, and in fact I have no idea whether that's true. Indeed, I have no idea whether very young infants even can experience pain. Certainly none of us remembers it, and if we're just going to forget it anyway, what difference does it make? All very philosophically deep.

Okay, interesting, not a big whoop. But it got me to thinking. What and why is pain? I have a friend who has some chronic pain problems -- sciatica and tendinitis -- and I once remarked to him that a more intelligent designer could have given us the functional equivalent of pain without making it actually, you know, hurt. In other words, we could get a warning signal -- like a flashing red light -- that told us that something was wrong -- don't put weight on that leg, pull your hand away from the fire, you've been cut, whatever -- without torturing us. Does that make any sense? Is the negative subjective experience of pain actually necessary?

Evolution, of course, doesn't care. If agony works, then that's what we get. And it's pretty obvious that in order for the less unpleasant signal to be effective, you need an intelligent creature that can link the signal to an undesirable outcome. "Oh, I guess I'd better do something about that wound before I bleed to death." You need, in other words, an intellectual understanding of what the implications would be of ignoring the signal, motivation to act, and a plan about what to do. Presumably less intelligent ancestors couldn't possibly have evolved such a system, so we're stuck with the one that did evolve. And anyway, there might be something circular about the idea. We have to be averse to the consequences of ignoring the signal, which means that something we consider painful is coming along down the road. If we can't feel pain, what's the point of life? Can we be conscious in any meaningful way without really feeling the pleasures of rewards and the agonies of punishment?

And sure, if we didn't have pain, we'd probably say, "Mañana, I'll get around to it." You know how it is.

So we need the hurt. It's what makes us alive, it's what makes experience. Without it we're just automata. The trouble is, much of the time, it isn't really doing the job it's supposed to do. It's just making us miserable and we can't do anything about it, or we don't know what to do about it, or we do the wrong thing about it. So pain is both friend or foe. Can't live with it, can't live without it.