Biased analyses of fMRI studies call into doubt some of the remarkably high correlations found between localised areas of brain activity and specific psychological measures. In other words, researchers have been seeing what they wanted and expected to see, and they’ve been unconsciously creating the experimentational circumstances in which their hunches are confirmed.
I’d long suspected that this was going on in a lot of epidemiological psychological studies, but I’m surprised to find it going on here.
That’s the first, and perhaps the least, of the two surprises. The second is altogether less expected and more of a nuisance.
It now appears that changes in the blood flow in the brain does not necessarily correlate with shifts in neuronal activity.
Why is that a nuisance? It’s a nuisance because we have instruments that can measure blood flow very accurately. We have made a great deal of progress in recent years in devising instruments to monitor brain activity. British science has been in the forefront of this. Now it turns out that measuring blood flow is all they do. We thought they were a window onto more fundamental neuronal changes. They aren’t.
But, as you might expect, one door closes… and if you read the rest of the piece, it’s clear that this has opened up a new line of enquiry:
The interpretation of human brain imaging experiments is founded on the idea that changes in blood flow reflect parallel changes in neuronal activity. This important new study shows that blood flow changes can be anticipatory and completely unconnected to any localised neuronal activity. It’s up to future research to find out which brain areas and cognitive mechanisms are controlling this anticipatory blood flow. As the researchers said, their finding points to a “novel anticipatory brain mechanism”.
I’ve always said that neuroscience was far from finding any real answers to the sort of questions we have now. All it’s doing is finding out what the questions actually are. This bears that out a little.
Well said. I always wondered how they control for “daydreaming” in these studies. Sure you’re showing me pictures of wolves and sheet, but I’m in a boring MRI tube so I’m thinking about that Kate Winslet film last night…
Err… wolves and sheep… freudian slip perhaps…
Gosh, an opportunity to trot out my wee aphorism:
“All medical research is rubbish” is a better approximation to the truth than almost all medical research.
We all have to choose the lesser of two weevils, Dearieme, and you’re dished: this isn’t medical research. (Hairsplitting done for the day…)