Brains Wired Differently in Men vs. Women


Men and women have long suspected that our brains are wired a bit differently. Now science is starting to back up this notion: A new study finds that men have more synapses connecting the cells in a particular part of the brain than women do.

But don't get cocky guys — the finding doesn't having any bearing on general smarts.

Broadly speaking, though, each sex tends to excel at different types of cognitive functions. Research has shown that men tend to do well at mental rotation of objects and spatial perception, whereas women tend to be better at verbal memory and fluency.

Neuroscientists have been examining brains to look for structural differences between the sexes that could explain these differences in abilities. Several studies in recent years have shown that men and women have different ratios of white and gray matter in their brains and different densities of neurons, or nerve cells.

The new study, conducted by researchers at the Consejo Superior de Investigaciones Cientificas in Madrid, looked even deeper into the brain's make-up and found differences in the density of synapses, the junctions between neurons that allow the cells to communicate with each other.

The researchers examined fresh brain tissue removed from epileptic patients during brain surgery with an electron microscope. (The findings don't apply only to epileptics though because the tissue was taken from apparently normally-functioning parts of the patients' brains. Also, it is unlikely that these differences between the sexes would be the result of epilepsy because all the patients were epileptic.)

They found that in the temporal neocortex, which is involved in social and emotional processes, men had a higher density of synapses than women.

The finding, detailed in the Sept. 8 issue of the journal Proceedings of the National Academy of Sciences, doesn't necessarily mean that men have more complicated brain circuits than women, the researchers cautioned in their article.

They added that more work will need to be done to see if the differences in synapse density are the same in other parts of the brain and to connect these differences to specific brain functions.

The study was funded by the Spanish Ministry of Education and Science, El Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, and the Cajal Blue Brain Project