We Cannot Explain Pain with Brain Scans

Not necessary for pain By timcocks0noi, April 27, 2016

This is the faulty reasoning being used as scientists try to find a “brain activity measure” with imaging to determine the existence and amount of our pain.

At the recent EP3, Giando Iannetti provided a quick lesson in a logical fallacy known as ‘Affirming the consequent’ with the following example:

  1. When Lorimer does the laundry he uses more electricity
  2. Lorimer is using more electricity
  3. Therefore Lorimer is doing the laundry

The conclusion 3. is invalid because it can be false even if 1. and 2. are true. In other words, there are multiple reasons Lorimer might be using more electricity (he could be vacuuming or blow drying his hair…).  

Giando raised this logical fallacy because of the corollary false argument:

  1. When a person experiences pain, certain parts of their brain are ‘active’ together
  2. Certain parts of this person’s brain are ‘active’ together
  3. Therefore this person is experiencing pain

Giando argued that 3. immediately above is also invalid because his group (and others) has shown that the same areas of an individual’s brain can be active when you provide very different stimuli – both nociceptive and non-nociceptive, and the individual reports very different subjective experiences.

Insula, Amygdala and Anterior Cingulate not necessary for pain

In a recent piece on Gizmodo, this idea is echoed by Tim Salomons – the lead author of a recent case study (open access). From the Gizmodo piece:

“I wouldn’t say that’s it’s wrong to say that the ‘pain matrix’ is involved in processing pain,” lead author Tim Salomons (University of Reading) told Gizmodo. “What’s wrong is the idea that it is specific to pain—in other words, that when you observe this pattern, you can’t just assume that person is in pain.”

From the paper:

“These results challenge the notion of a “pain matrix” and provide direct evidence that the insula, anterior cingulate, and amygdala are not necessary for feeling the suffering inherent to pain”

A cautionary note

The excellent work done by people like Giando and Tim Salomons (and their teams) should be a cautionary note for anyone in the business of Explaining Pain to avoid simplistic and inaccurate metaphors.

Further, these findings sound a challenge to keep up to date with the foundational neurosciences, while at the same time exercising some healthy skepticism and critical thinking – no trivial task indeed.

 

2 thoughts on “We Cannot Explain Pain with Brain Scans

  1. Pingback: Unlearning pain can reverse brain changes | EDS Info (Ehlers-Danlos Syndrome)

  2. Pingback: Neuroimaging in Chronic Pain Management | EDS Info (Ehlers-Danlos Syndrome)

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