By IANS,
Washington : Men outperform women on spatial tasks, including the ability to identify how a 3-D object would appear if rotated in space, claims a new study.
The University of Iowa (UI) study shows a connection between this sex-linked ability and the structure of the parietal lobe, the brain region that controls this type of skill.
The parietal lobe was already known to differ between men and women, with women’s parietal lobes having proportionally thicker cortexes or “grey matter”. But this difference was never linked back to actual performance differences on the mental rotation test.
UI researchers found that a thicker cortex in the parietal lobe in women is associated with poorer mental rotation ability, and in a new structural discovery, that the surface area of the parietal lobe is increased in men, compared to women.
Moreover, in males, the greater parietal lobe surface area is directly related to better performance on mental rotation tasks.
“It’s important to note that it isn’t that women cannot do the mental rotation tasks, but they appear to do them slower, and neither men nor women perform the tasks perfectly,” said Tim Koscik, the study’s co-author and a graduate student at UI.
The study was based on tests of 76 healthy Caucasian volunteers, 38 women and 38 men, all right-handed except for two men, said an UI statement. The results were published online by Brain and Cognition.
The groups were matched for age, education, IQ and socioeconomic upbringing. When tested on mental rotation tasks, men averaged 66 percent correct compared to 53 percent correct for women.
Magnetic resonance imaging (MRI) revealed an approximately 10 percent difference between men and women in the overall amount of parietal lobe surface area: 43 square centimetres for men and 40 square centimetres for women.
The findings underscore the fact that not only is the brain structure different between men and women but also the way the brain performs a task is different, said Peg Nopoulos, a study co-author and professor of psychiatry and paediatrics at the University of Iowa Carver College of Medicine.