Biology matters: Male and female brains have distinct differences in architecture, activity and function, say scientists

Much has been said about the supposed similarities between males and females over the past few decades. However, the science has always been quite clear. Biologically speaking, there are only the male and female genders. There’s no such thing as “gender fluidity” except as an imaginary construct. Now new research on the human brains reveals secrets about just how different the two genders truly are.

Researchers from Semmelweis University looked into the so-called hemispheric lateralization of sleep spindles in a number of healthy human subjects. Their study included both male and female participants, which is why they were able to note some key differences between them. What they found was that there were clear differences between the behavior of each gender’s brain as far as their respective sleep spindles are concerned.

The researchers found evidence for asymmetrical distribution of sleep spindles over the two hemispheres of the subjects’ brains.  What’s more, this phenomenon was found to be sexually dimorphic as well as region-specific. This signifies clear differences in neurocognitive architectures between the two sexes.

The researchers went over their findings in great detail. Males and females were found to be different in the sense that they each have distinct spindle oscillations. They differ in the hemispheric lateralization of their neurocognitive processes as well, according to the researchers.

Although there have been many previous studies on the topic of hemispheric lateralization of so-called spindle oscillations, there had been no reported differences in the hemispheric lateralization of sleep spindles based on either sex or age. The researchers set out to fill this gap by the description of the hemispheric lateralization of sleep spindles in healthy human subjects. To do this, they conducted a retrospective multi-center study that took and unified data from three distinct groups: N?=?251, age range: 4?69 years, 122 females.

The researchers also analyzed the amplitude, density, and duration of slow (frontally dominant) and fast (centroparietally dominant) spindles by using the individual adjustment method. Then hemispheric lateralization was quantified with the (L???R)/mean (L, R) index. What they found was quite revealing.

According to the researchers, data from their subjects clearly showed that orbitofronto-temporo-occipital and parietal fast sleep spindle measures are left lateralized, while prefrontal spindle amplitude is characterized by right hemispheric dominance. At the same time, with each increase in the age of a male, there is an increase in the fast spindle density’s left lateralization as well as the duration in the temporal and orbitofrontal regions. The same could not be said for females.

Females were said to be different in that they are characterized by higher left hemispheric dominance in occipitally measured fast spindle durations as opposed to males. This behavior in either sex shows exactly how different the two operate in terms of brain activity. Age didn’t really play into it apart from what was noted regarding the fast spindle density’s left lateralization in males as they grow older.

Based on the data from the research, there are major differences between men and women on a fundamental level. After all, the researchers found the most clear distinctions in deep-level brain activity, function, and architecture. That could go a long way towards explaining how men and women don’t always seem to speak, act, and think alike. The researchers didn’t go as far as to say exactly what their research should mean for humanity moving forward as a species, but at least it can serve as a useful guidepost for other future studies.

Sources include:

Science.news

TheAtlantic.com