Monday, June 21, 2010

Silly Talk About the Brain & Pleasure Centers

Sydney Lamb begins Pathways of the Brain with a story about his daughter (p. 1):
Some years ago I asked one of my daughters, as she sat at the piano, "When you hit that piano key with your finger, how does your mind tell your finger what to do?" She thought for a moment, her face brightening with the intellectual challenge, and said, "Well, my brain writes a little note and sends it down my arm to my hand, then my hand reads the note and knows what to do." Not too bad for a five-year old.
Lamb goes on to suggest that an awful lot of professional thinking about the brain takes place in such terms (p. 2):
This mode of theorizing is seen in ... statements about such things as lexical semantic retrieval, and in descriptions of mental processes like that of naming what is in a picture, to the effect that the visual information is transmitted from the visual area to a language area where it gets transformed into a phonological representation so that a spoken description of the picture may be produced....It is the theory of the five-year-old expressed in only slightly more sophisticated terms. This mode of talking about operations in the brain is obscuring just those operations we are most intent in understanding, the fundamental processes of the mind.
I agree with Lamb whole-heartedly. My impression is that most of the neuroscientific effort goes into getting observations – using some really cool technology, too – but when it comes to thinking about what's going on, the inner child just takes over – and a rather dim one at that.

Some talk of pleasure centers, for example, strikes me as being equally dim. This kind of talk asks you to imagine that there is some center in the brain which, when stimulated, gives you pleasure. Call it the P-Center. Such talk is grounded in a misinterpretation of some interesting experiments James Olds did back in the 1950s – which I discuss in Beethoven’s Anvil (pp. 82-85).

Let’s exaggerate and be explicitly and extravagently silly. Imagine that the P-Center is in the middle of your left palm. In order to experience pleasure it must be stimulated by pleasure juice (P-Juice), which is made in the salivary glands. So, to experience pleasure you spit into your left palm and – ZAP! – you get jolt of pleasure.

Silly, no? – I mean, there’s no chance we’re being serious, right? So let’s go on.

You might wonder why Mother Nature would create such a scheme, which could threaten survival. How? Well, if you can get pleasre so easily, you’d probably spend all your time spitting P-Juice into your palm and neglect eating and drinking and sleeping, and so forth. After all, no matter what happens, you just spit in your palm and Violà! pleasure is yours – a problem Bill Powers pointed out in Behavior: The Control of Perception.

So, let’s imagine that Mother Nature, in her wisdom, made the production of pleasure juice contingent upon some concrete achievement. That is, you have to do something that has survival value in order to produce P-Juice. Imagine, for example, that you chase down a rabbit. The brain’s Evaluator says “Ah! a warm meal” and tells the P-Juice gland to produce some P-Juice. The P-Juicer does so and tells the Spitter “Yo yo yo, spit in the palm, NOW!” The Spitter does it and the P-Center tells the Evalulator, “We got pleasure here.”

But this whole thing started with the Evaluator. So why have all this other mess about P-Juice and a P-Center? Why not have the Evaluator produce pleasure directly? Why indeed. But the underlying problems of such talk doesn’t stop people from believing in pleasure centers.

But what about pleasure itself, you ask, what IS it, for real?

Good question. Later. Or just read Chapter 4 of Beethoven’s Anvil.

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