Sunday, October 16, 2005

Neuromatrix 4: The Evolution of New Concepts

More from Melzack:

Progress in science, according to historians of science such as Thomas Kuhn, occurs in two ways: by the gradual accumulation of information that we call ‘facts’ and by the rapid jumps in the integration of facts that occur when a new theory, concept, or ‘paradigm’ is proposed..... The power of theory was summarized briefly by Donald O. Hebb: ‘The “realworld” is a construct, and some of the peculiarities of scientific thought become more intelligible when this fact is recognized... Einstein himself in 1926 told Heisenberg it was nonsense to found a theory on observable facts alone: ‘In reality the very opposite happens. It is theory which decides what we can observe.’ ...

In the case of pain, theory not only determines what we observe in physiology, but it determines how we treat people in pain. We now know that neurosurgical lesions to abolish chronic pain usually fail and the pain tends to return. Yet theory and so-called facts about pain fibres and pathways said they should work..

(Just like the gate control theory Melzack and Patrick Wall determined 40 years ago (1962) has been PT paradigm ever since, I guess... so-called gate theory says that electrotherapy should work, yet there is a lot of 'anomalous data' i.e. a lot of people we treat that it doesn't work for beyond some temporary novelty experience... according to Kuhn in a subtext on page 6, it is the accumulation of anomalous data that forces the formation of a new paradigm/theory.)

Descartes’ views have so thoroughly permeated our concepts about physiology and anatomy that we stilll cannot escape them. In addition to the concept of a specific pain projection system, Descartes left us another legacy that has perverted our understanding of how the nervous system works....suggesting mechanical, immutable laws... In the normal world, perception and behavior are highly variable... Behaviorism, which ignored the brain and its functions, is vanishing; cognitive psychology, which recognizes the variability of perception, the malleability of memory, thought, and imagery, has now become the dominant concept.

This new approach in psychology is, happily, being paralleled by major changes in our views of brain function. We now know that the brain possesses widely distributed, parallel processing networks and that it produces an excess of neurons and synapses, so that we can conceive of memory as a sculpting process rather than a slow ‘cementing’ of synapses. This new, dynamic picture of the brain is gradually having an impact on our understanding of pain.

More to come.

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