Scientists have proven the hypothesis of different brain structures in men and women

The findings will help account for differences in the treatment of neuropsychiatric disorders

All doubts about the morphological structure of our main organ depending on gender have been dispelled. Artificial intelligence has learned to distinguish a woman's brain from a man's brain with 90% accuracy. A program made at Stanford identified three “zones of difference” in the brain that work differently when performing the same tasks. Firstly, this is the so-called passive mode network of the brain, which works for us in the absence of interaction with the outside world, secondly, the striatum, responsible for motor activity, and thirdly, the limbic system of the brain, which responds to more subtle perception of the world, smells, differences in shades, emotions. The work was published in the Proceedings of the National Academy of Sciences. We asked Russian scientists to comment on this discovery.

Photo: Alexey Merinov

So, if previously it was believed that the brains of men and women are the same, and the opinion about their differences is formed solely by influence of the standards accepted in society, now everything has fallen into place — there are differences.

According to American scientists, it was not possible to prove this for a long time, since the morphological structures of the brain in representatives of both sexes are very similar. And only thanks to artificial intelligence, which was used in a new study, specialists still managed to classify the contents of our skull.

First, the neural network was “trained” by showing 1,500 dynamic images of the brain taken on a functional MRI, that is, , brains of men and women working on the same tasks. The neural network, thanks to such a large data set, identified certain patterns, and then easily distinguished a working female brain from a working male one. In this analysis, the brain was divided into 246 different regions.

The brain function was most different when it was in passive mode, when the person was immersed in himself. Additionally, differences were best seen in the striatum and limbic system. In particular, the latter is responsible for the emotional component of a person; it is not for nothing that women have more developed abilities for a more subtle perception of any life situation, they perceive smells more subtly, and are more empathic.

A fairly precise division of the brain into male and female will help, according to the author of the work, director of the Stanford Laboratory of Cognitive and Systems Neuroscience Vinod Menon, to take into account sex differences in the future in the treatment of neuropsychiatric disorders.

– We have long known about the differences in the functioning of the brains of men and women. Let's start with a 2014 paper that identified morphological differences using diffusion tensor imaging. Scientists looked at the structural connectome—the connections between structures, or modules, of the brain. So, the connectivity in the brains of men and women turned out to be different. In men, the modules can work independently without affecting each other. In women, on the contrary, the modules have a high degree of connectivity, both within the hemisphere and between the hemispheres. This is a fundamental difference.

At one time we looked at the characteristics of working memory in men and women. For example, when comparing an object we have already seen and a similar new one. It was shown that the brains of women and men worked differently. In women, the prefrontal and limbic systems worked more (as I understand, this was also shown by the latest study at Stanford), and in men, the occipital and parietal cortex worked more. We have also identified gender specificity of brain function in other situations, for example, when performing visual-spatial activities. In men, problems were solved quickly, almost on an intuitive level; in women, we observed later conscious processing of information.

Morphological differences between male and female brains were known in both the USA and Russia about 20 years ago. I was defending a doctoral student on sex differences in the mammillary bodies of the limbic system. The mastoid structures integrate a lot of functional connections, and in particular, are associated with human sexual behavior. They turned out to be very different in cellular composition and in the rate of aging. This happens faster in women, slower in men.

As for the work under discussion, I believe that it was done “dirty” and its reliability raises questions. It leaves out very important things. For example, the striatum, which is responsible for motor-motor coordination, control of posture and everything else, can individually differ in size by 3-4 times in different people; its activity is associated with the complexity of the movements that a person was engaged in before the study, and therefore not may be a sign of gender differences. Let's move on to the limbic system. It's very big. It includes about two dozen basic structures associated with the hormonal regulation of behavior. Therefore, in women, when studying the activity of the limbic system, it is necessary to monitor the state of sexual cycles. In addition, the internal structures of the limbic system can differ individually by 3-4 times, for example the hippocampus and its sections that are responsible for emotions.

– An article by scientists from the United States who used AI algorithms to analyze functional magnetic resonance imaging data made it possible to record the metabolic activity of various parts of the brain. This is a type of MRI that reflects the energy status of tissues and, therefore, their activity at a given time. In itself, the fact of gender differences in the functional characteristics of the brain of men and women is not surprising — we differ genetically (women have no Y chromosome) and, as a consequence of this, in a whole range of endocrine and biochemical indicators. All this, of course, affects the functions of the central nervous system — the spectrum and ratio of neurotransmitters, fine tuning of the signaling systems of brain cells. It is also not surprising that the most significant differences were recorded for the ancient structures of the brain, which are responsible, among other things, for the emotional coloring of behavior — the striatum (striatum) and the limbic system, which are the depot of the most important neurotransmitters (hormones in the brain that transmit information from one neuron to another), including dopamine. The main advantage and prospects for the applied use of the results of this study is the development of an algorithm for analyzing MRI data. This kind of data will accumulate in huge quantities as a result of clinical studies and will provide a wealth of material for obtaining new knowledge about the functioning of the brain and other organs. And this is already a step towards the development of new methods for precision diagnostics of pathologies. It is worth thinking about creating a structured system of similar databases and algorithms for their analysis in Russia, although methods using AI are already being developed by domestic scientists.