A small study has found that the brains of men and women are wired differently in a region that is related to speech, memory, and hearing. Researchers studied the brain tissue from four men and four women who were all having a small portion of their brains excised as a treatment for epilepsy. They found that in the brain region called the temporal neocortex, men have a higher density of synapses, which are the connection points between brain cells.
For many years, scientists have searched for structural variations between men’s and women’s brains to explain psychological studies showing that, overall, the sexes think and act differently. Past studies found differences in brain mass and neuron density, but “they were hyped and untrustworthy,” [neuroscientist Edward] Jones says. This study is meticulously detailed, he notes. It is the first to show gender differences on such a fine scale — at the synapse [Science News].
The study, published in the Proceedings of the National Academy of Science [subscription required], was careful not to draw conclusions about what this structural difference might mean for brain function, and said that the higher number of synapses in men’s temporal neocortex did not indicate any overall advantage in intelligence. Study co-author Javier De Filipe said that the difference in synapses was “very consistent” and surprising, though he stressed that in other regions of the brain women may have more connections. Other work said that the anterior commissure, which connects several regions of the frontal and temporal lobes, is 12 per cent larger in women than in men, for example [Telegraph].
Some experts even suggested that the smaller number of synapses in the temporal neocortex of women might actually be an asset. “We know that the temporal cortex is involved in language processing, and that women and girls have a slight behavioral advantage in this area,” said [neuroscientist] James Booth…. “In this case ‘less may be more.’ In other words, fewer synapses to other regions may represent increasing specialization of the temporal cortex for language processing in females, and this may be related to their overall better performance on language tasks” [Bloomberg].