Saturday, June 6, 2020

Creation Moment 6/7/2020 - fMRI Debacle

"Studies of Brain Activity Aren’t as Useful as Scientists Thought (Duke University).

For years, neuroscientists have merrily observed their patients
perform tasks in MRI machines, figuring out how the brain works. The MRI machine records the data obediently, yielding nice images of blood flow, a proxy for brain activity in a well-known, highly-trusted process known as “functional MRI” (fMRI). Well, that proxy orthodoxy has just collapsed. Look what the press release from Duke U says:
Hundreds of published studies over the last decade have claimed it’s possible to predict an individual’s patterns of thoughts and feelings by scanning their brain in an MRI machine as they perform some mental tasks.
But a new analysis by some of the researchers who have done the most work in this area finds that those measurements are highly suspect when it comes to drawing conclusions about any individual person’s brain.
Even readings taken on the same person a few weeks or months apart can be so different as to be useless for drawing conclusions. Look how bad this is. The correlations don’t even rise to “fair” like a C grade; they’re more like a D or F, according to Ahmad Hariri, a professor of psychology and neuroscience at Duke University who led the reanalysis.
Functional MRI measures blood flow as a proxy for brain
activity. It shows where blood is being sent in the brain, presumably because neurons in that area are more active during a mental task.
The problem is that the level of activity for any given person probably won’t be the same twice, and a measure that changes every time it is collected cannot be applied to predict anyone’s future mental health or behavior.
Hariri and his colleagues reexamined 56 published papers based on fMRI data to gauge their reliability across 90 experiments. Hariri said the researchers recognized that “the correlation between one scan and a second is not even fair, it’s poor.”
The best that can be done is to test a large number of people and compute averages, the article says, but how can that be? Bad data based on wrong presumptions averages out to bad averages, it would seem. Hariri is flabbergasted by this revelation.
This is more relevant to my work than just about anyone else’s!” Hariri said, his voice rising. “This is my fault.
I’m going to throw myself under the bus. This whole sub-branch of fMRI could go extinct if we can’t address this critical limitation.”
Hariri has been using fMRI data as part of a long-term study of 1,300 undergraduate Duke students. By combining brain scans, genetic testing and psychological assessments, Hariri is searching for biomarkers of individual differences in the way people process thoughts and emotions, such as why one person comes away from a traumatic event with PTSD or depression and another does not.
“We can’t continue with the same old ‘hot spot’ research,” Hariri said. “We could scan the same 1,300 undergrads again and we wouldn’t see the same patterns for each of them.”
In short, fMRI is completely unreliable for what neuroscientists and psychologists thought it was showing. All those papers go out the window. Should Hariri be fired? Pulling himself out from under the bus, he tries to think of ways to carry on somehow. His colleague Russell Poldrack, a psychologist at Stanford who is also guilty of publishing phony fMRI “scientific findings” tries to help:
There’s three things you can do,” Poldrack said. “You can just up and quit, you can stick your head in the sand (and act as if nothing has changed), or you can dig in and try to solve the problems.
It’s an admirable spirit. But neither Poldrack or Hariri seem to know what exactly to do. Maybe they could follow the adage, “When in trouble, when in doubt, run in circles, scream and shout.” That should cause some interesting images of blood flow in the MRI scanner."
CEH
And the LORD God formed man of the dust of the ground,
and breathed into his nostrils the breath of life; and man became a living soul.
Genesis 2:7