Sunday, June 23, 2013

Melzack & Katz, Pain. Part 10: "We don't need a body to feel a body."- Melzack, 1989

The paper, Pain

Part 1 First two sentences Part 2 Pain is personal Also Pain is Personal addendum., Neurotags! Pain is Personal, Always.

Part 3a Pain is more than sensation: Backdrop Part 3b Pain is not receptor stimulation Part 3c: Pain depends on everything ever experienced by an individual

Part 4: Pain is a multidimensional experience across time

Part 5: Pain and purpose

Part 6a: Descartes and his era; Part 6b: History of pain - what’s in “Ref 4”?; Part 6c: History of pain, Ref 4, cont.. : There is no pain matrix, only a neuromatrix; Part 6d: History of Pain: Final takedown Part 6e: Pattern theories in the history of pain Part 6f: Evaluation of pain theories Part 6g: History of Pain, the cautionary tale. Part 6h: Gate Control Theory.

Part 7: Gate control theory has stood the test of time: Patrick David Wall;  Part 7bGate control: "The theory was a leap of faith but it was right!"
Part 8: Beyond the gate: Self as mayor Part 8b: 3-ring circus of self Part 8c: Getting objective about subjectivity
Part 9: Phantom pain - in the brain! Part 9b: Dawn of the Neuromatrix model Part 9cNeuromatrix: MORE than just spinal projection areas in thalamus and cortex Part 9d: More about phantom body pain in paraplegics

We are still "Beyond the Gate", working our way through the section, "Phantom Limbs and the Concept of a Neuromatrix." We still have a long long way to go before this little river finds its lake or ocean, but I'd say we're a good third of the way there. Thank you to anyone who has hung in there this long, as I meander all over the place. [Both of you.] 

"We don't need a body to feel a body."

We pick up at the next paragraph after "Despite this increased knowledge, we do not have yet an adequate theory of how the brain works", before we backtracked into paraplegic phantom body pain, yesterday:
"Melzack's19 analysis of phantom limb phenomena, particularly the astonishing reports of a phantom body and severe phantom limb pain in people with a total thoracic spinal cord section,17 led to four conclusions which pointed to a new conceptual model of the nervous system. 
We know by now where Reference 17 goes.. just see yesterday's post.

Reference 19 goes to 
Melzack R. Phantom limbs, the self, and the brain (The D.O. Hebb memorial lecture). Canad Psychol 1989, 30:116. (Full pdf) This paper examines the issue of phantom penises, breasts, bladders, rectums, arms, legs, and in paraplegics, phantom bodies below the level of lesion, fully and with references. It's 16 pages long, and well worth a long meander. It contains his four conclusions in as much or more detail than I've ever seen anywhere else. The rest of the paragraph is spread out below. Excerpts from the Melzack and Katz paper will be in a different colour from the excerpts from the very juicy 16 page long Canadian Psychology paper from 1989. But we shall cover each conclusion in some depth. Each conclusion might even become one or more blogposts. 

"First, because the phantom limb feels so real, it is reasonable to conclude that the body we normally feel is subserved by the same neural processes in the brain as the phantom; these brain processes are normally activated and modulated by inputs from the body but they can act in the absence of any inputs. 

Second, all the qualities of experience we normally feel from the body, including pain, are also felt in the absence of inputs from the body; from this we may conclude that the origins of the patterns of experience lie in neural networks in the brain; stimuli may trigger the patterns but do not produce them. 

Third, the body is perceived as a unity and is identified as the ‘self’, distinct from other people and the surrounding world. The experience of a unity of such diverse feelings, including the self as the point of orientation in the surrounding environment, is produced by central neural processes and cannot derive from the peripheral nervous system or spinal cord. 

Fourth, the brain processes that underlie the body-self are ‘built-in’ by genetic specification, although this built-in substrate must, of course, be modified by experience, including social learning and cultural influences. These conclusions provide the basis of the conceptual model18,19,21 depicted in Figure 3."


It's crazy, I realize, but I can't help feel excited about this.

Yeah, it's old, it's dusty, but I love it, and I really don't care if no one else does. I love poking around inside Ronald Melzack's mind.


Mark Hollis said...

Isn't it an assumption that it's both of us readers ... it may be the same person reading it twice :). Great blogposts Diane as per the u (and yes i have read them more than twice). The implications of this paper are mindbendingly HUGE !

Diane Jacobs said...

Yeah, I know... huge.
Thanks for being a reader.