Schizophrenic men have more female brains and vice versa

Apr 1, 2008 19:51 GMT  ·  By
Differences in activation of brains, in white, of men (top row) and women (bottom row) schizophrenics
   Differences in activation of brains, in white, of men (top row) and women (bottom row) schizophrenics

If men and women differ behaviorally, this has an anatomical base. More specifically: the brain of the man differs from that of the woman. The differences are slight, but the impact is great. This explains why men have higher ability to visualize objects in three dimensions or read maps, labyrinths and diagrams, but they find it harder to read facial expressions. Several studies showed that the brains of the gay men are "more female", while the brain of the lesbian women are "more male", showing that the sexualization of the brain is involved in sexual behavior and preference. A new research shows the same reversal of the gender differences in the brains of schizophrenics.

"In comparison to the general population, women's brains seem masculine and men's brains seem feminine," said author Adrianna Mendrek, a researcher from the Centre de recherche Fernand-Seguin that is affiliated with the Universit? de Montr?al's Department of Psychiatry.

Woman's brain has more developed structures and circuits involved with emotion. Women have a wider corpus callosum, the major white matter tract, connecting the two brain hemispheres, allowing their intercommunication. That's why women have their brain functions better distributed, while men have a more "asymmetrical" brain, with more specialized areas and that's why, for example, a lesion (like a stroke) on the left hemisphere, which can induce speech loss, is more devastating for men.

Mendrek investigated the reaction of the schizophrenics' brain to some emotional stimuli. The subjects watched two films: the first was sad, and the second displayed anger. The brain fMRI of the schizophrenic subjects showed that male brains were affected by the sad movie, while the female schizophrenic brains remained not turned on by those sequences. The angry scenes triggered more complex and intense brain activation in men.

"These results are surprising seeing as women are usually more emotionally expressive than men. The differences aren't the result of drugs or of subjective past experience seeing as the emotions were felt identically in all subjects. The profiles of activation in women would indicate that they have more difficulty integrating cognition and emotion associated to stimuli related to empathy," said Mendreck.