Functional magnetic resonance imaging by Washington Irving, public domain
In an article in the Washington Post on 8/2/23, cultural
critic Kristen Martin wrote an essay about how some best-selling books express great confidence in
theories of the brain that are in reality still in their infancy - and unproven. She mentions a
book I reviewed, The Body Keeps the Score
by Bessel van der Kolk, a well as The
Grieving Brain by Mary-Francis O’Connor.
The
author believes that “neuroscientific wisdom is now recirculating into new
mediums, calcifying into consensus that we can’t stop parroting.”
In
reality, our understanding of the human brain, while increasing rapidly, is still in
its infancy. Scientists have to contend with about a trillion
connections between billions of brain cells that constantly change in response
to the input of literally thousands of environmental and interpersonal
influences (neural plasticity). I
have written several times about how this problem manifests itself in studies
using a type of brain scan called an fMRI, which basically measures blood flow
in parts of the brain as the brain’s owner is engaged in a variety of mental
tasks.
Another doctor likened trying
to make any generalizations about repetitive behavior from observable
differences in brain scans to trying to know how the stock market is doing by
measuring electricity usage at the stock exchanges.
I
write about how results that differ between groups are labeled as “abnormalities”
when in fact they might indicate normal differences in the performance of the task
in people who have had differing prior experiences and have learned to approach the task in
different ways. They may be accomplishing differing goals - and without having
to engage in conscious deliberations.
Martin also says that
people consult neuroscience to validate what they want to believe or what they
already know. “Tracing all of our messy emotions, reactions and habits to the
workings of electrical currents and neurochemicals lets us off the hook.”
She
references some work with brain scans that adds even more fuel to our opinions
on the matter. In 2009, a neuroscientist put a dead salmon through an fMRI and detected
activity in its dead brain. It is easy to produce a false positive finding just
from statistical noise in the scans.
She
adds, “A scan can correctly identify the areas of a person’s brain that are
receiving blood flow at a particular moment, but we can’t definitively say that
activation of a brain region equals a particular emotional or cognitive state.”
A part of the brain called the amygdala produces negative emotions like fear,
but also positive ones, like happiness.
Even
more striking was a review from 2020 by Duke University professor Ahmad Hariri.
It reanalyzed 56 published academic studies based on fMRI analyses, and found
that the results usually do not come out the same on a second scan.
As
I have also written about extensively, misleading fMRI study results are
routinely injected into the still highly prevalent nature-nurture debates in
psychology and psychiatry. Genetic influences on behavior are routinely exaggerated
by the field in conclusions that are based on brain scan research.
