Tuesday, January 22, 2008

What is a neuromatrix?

Readers frequently ask about the definition of neuromatrix in relation to the brain and pain. Wikipedia and Google are not that helpful (yet), though there are some good links on Google to Ronald Melzack’s pioneering work. (Melzack, 1999, 2001).

Cognitive Psychology is merging to some degree with neurobiology. While the term neuromatrix has emerged with the increasing knowledge of brain neuroscience, some of the older cognitive psychology writings provide good definitions and understanding of what we now call the neuromatrix.

I like “a map of event space in the system’s coding space” (Dudai, 1989). So the coding space is all the possible combinations of connections in the brain. Pain or jealousy could be an event which would take up part of this space. The event space has been referred to by Melzack as the neurosignature. So a pain neurosignature exists within the neuromatrix. Moseley and I (Butler & Moseley, 2003), trying to be a bit trendy, refer to the neurosignature as a neurotag.

Of course it is all far more complex than this. A pain neurotag exists in a snapshot of time. It will change over time and context. Everyone’s pain neurotags are different and even our own pain neurotags will be structurally different within the brain over time.

The term “representation” is also used in relation to neurosignature.

Hoping this makes sense!!

Butler, D. S., & Moseley, L. S. (2003). Explain pain. Adelaide: NOI Publications. Dudai, Y. (1989). The neurobiology of memory. Concepts, findings, trends. Oxford: Oxford University Press. Melzack, R. (1999). From the gate to the neuromatrix. Pain, Suppl 6, S121-S126. Melzack, R. (2001). Pain and the neuromatrix in the brain. Journal of Dental Education, 65, 1378-1382.