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[1] I’ve seen this article being thrown around a lot at the moment, which claims to “debunk” the notion of male and female brains, and how any observable difference is due to societal/gendered influence. Once again, this is incorrect. https://www.nature.com/articles/d41586-019-00677-x
[2] Analysing sex differences in the brain requires a multivariate approach, much like facial recognition. There is no unifying male or female face, however, facial recognition software can determine the difference via bone structure and many others. The brain is no different.
[3] Using this approach of measuring different domains of the brain, researchers can accurately predict biological sex from an individual brain scan using a multivariate analysis and machine learning algorithms. Again, no unifying feature, but we can still tell the difference.
[4] This study uses machine learning and a multivariate approach to predict sex based on brain scans with 93% accuracy. https://pubmed.ncbi.nlm.nih.gov/30430711/
[5] So does this one.
“The proposed 3D PCNN model achieved 93.3% classification accuracy in the whole-brain FA.” https://www.frontiersin.org/articles/10.3389/fnins.2019.00185/full
“The proposed 3D PCNN model achieved 93.3% classification accuracy in the whole-brain FA.” https://www.frontiersin.org/articles/10.3389/fnins.2019.00185/full
[6] Understanding these differences is important when considering discrepancies in neuro and psychiatric conditions (depression, anxiety, ADHD, autism & dyslexia). Differences in the brain can explain why men & women differ in terms of diagnosis numbers.
[7] E.g. Serotonin receptors differ between the sexes, explaining depression discrepancy.
“Compared to men, women had significantly higher 5-HT(1A) receptor and lower 5-HTT binding potentials in a wide array of cortical and subcortical brain regions” https://pubmed.ncbi.nlm.nih.gov/18036835/#:~:text=Compared%20to%20men%2C%20women%20had,for%20the%20region%20of%20hippocampus
“Compared to men, women had significantly higher 5-HT(1A) receptor and lower 5-HTT binding potentials in a wide array of cortical and subcortical brain regions” https://pubmed.ncbi.nlm.nih.gov/18036835/#:~:text=Compared%20to%20men%2C%20women%20had,for%20the%20region%20of%20hippocampus
[8] Differences are due to organisational and activational effects of sex hormones (androgens) in utero. These androgens lay the foundation of sex-based brain differences from neurogenesis (adult born neurons) to gene expression via transcription factors. https://pubmed.ncbi.nlm.nih.gov/19207813/
[9] Sex based brain differences are NOT due to society. Males & females show differences in personality, behaviour, and interests (Big 5 model and “things vs people”). These differences increase rather than decrease as societal influence minimises (as seen in Scandinavia).
[10]
1) Personality
https://pubmed.ncbi.nlm.nih.gov/30206941/
2) Interests https://pubmed.ncbi.nlm.nih.gov/19883140/
1) Personality
https://pubmed.ncbi.nlm.nih.gov/30206941/
2) Interests https://pubmed.ncbi.nlm.nih.gov/19883140/
[11] It needs to be noted these differences are only based on averages in degree. However, all these “degrees” add up, making it easy to identify male & female brains. All these sex and gender differences are measured via bimodal distributions…
[12] … which allow us to see how much men & women differ. The two sexes are more the same than different. However, at the extreme tail ends of the bimodal distribution are where the biggest differences are found. https://www.researchgate.net/publication/329701788_Measuring_Sex_Differences_and_Similarities
[13] Lastly, from this multivariate perspective, we can see how (on average) male & female brains differ. This helps us to understand how to treat neuro & psychiatric conditions in a sex specific manner and better understand the functional differences between us.
