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40,000 fMRI studies to throw away!

A research team recently revealed what they called a Cluster failure.

Most functional MRI studies conclusions may be erroneous because of their statistical basis. Widely used clustering inference techniques are actually pretty bad at properly inferring clusters due to “spatial autocorrelation functions that do not follow the assumed Gaussian shape”.

It means that “most common software packages for fMRI analysis (SPM, FSL, AFNI) can result in false-positive rates of up to 70%”… suggesting that some results were so inaccurate they could indicate brain activity that does not exist at all!. What is interesting is that neuroscientists are interpreting what they’re told by the statistical software rather than images.

These findings speak to the need of validating the statistical methods being used in the field of neuroimaging.

Therefore, 15 years of research on brain functioning could be invalidated!

But the issue is not limited to research but also extends to clinical use that is pretty worrying.

 

Image credits: fMRI by OpenStax from the Textbook OpenStax Anatomy and Physiology Published May 18, 2016




Women and men do have the same brain

Brain

I often hear that “boys and girls doesn’t have the same brain”. In fact, it is not true.

Brain

In a recent study, the connectome “showed few differences in connectivity up to the age of 13, but became more differentiated in 14- to 17-year-olds” between women and men, explaining some observable general differences. Moreover, it does mean that the observable difference can neither be generalized to all women and men nor imputed to a biological determinism. In other words you can meet less than 5 girls out of 10 who have a “man’s brain” and less than 5 men out of 10 who have a “woman’s brain” (supposing that these typical brains exist…), these people are normal and not infrequent… and the mean difference is not necessarily due to a genetic or hormonal determinism.

Talking in my capacity as graduate in cognitive science and former master’s student in neuroscience, I can claim that the brain is mainly a social construct.

The brain is a social construct

social interaction

The first argument is that, like many scientists have proven, the biological sex should not be seen as a dichotomy but rather as a continuum. If typical women and men existed by essence then they would both have a functionally distinct brain. Fortunately, each cognitive functions can range between two extremes that are not determined by the biological sex.

For the second argument I can confirm that there is no anatomical difference between foetal brains. In the adulthood, the structural scheme of the brain is the same except for control structures of physiological functions and reproduction. You may find more differences between two male brains than between a female and a male brain (exactly like the genomic differences that are likely to be as numerous between two white people as between two randomly selected black and white people).

The third argument is: the only observable differences (that are statistically significant) are a social construct.

Remember the citation about the connectome? The difference appears by 14-17. It doesn’t seem to support the idea that the brains are wired differently from start.

So far, I have never seen an article claiming to prove a chemical or structural difference which doesn’t suffer from a bias. The only sexual differences are actually gender difference, socially induced in every species (read here and here)… which affects the way we behave. Humans are able to bypass genetic and hormonal determinisms.

If you make an effort, thanks to neural plasticity, you can unmake a learned difference. Think about it the next time you will consider a behavior as a natural one…