Women's balanced brains have the last word

BY TOM WILKIE

Science Editor

When it comes to talking, women's brains work differently to men's, according to scientists from Yale University.

Bennett Shaywitz and a team of US researchers have produced the first clear evidence that males and females differ in the way their brains are organised for language. The results, reported in today's issue of the scientific journal Nature, reveal that men tend to use the left hemisphere of their brains when thinking about language. Women use more of their brains when it comes to language, with the processing more generally distributed across both hemispheres.

The latest instance of gender differences in the brain comes just a few weeks after another study which suggested women and men use different areas of their brains when it comes to emotion. Men are more "lizard-like" in handling emotions, employing centres of the brain that developed early in evolution, whereas women employ more recent mammalian structures to handle emotion.

The technique used by the researchers to analyse language represents "a major breakthrough" in imaging the human brain while it is working, according to Professor Michael Rugg, of the School of Psychology at St Andrews University. They mapped the flow of oxygenated-blood into active areas of the brain by detecting tiny magnetic fields given out by the atomic nucleus of the oxygen in the haemoglobin of the blood.

Previous attempts to image the brain relied on injecting mildly radioactive tracers into the blood and measuring the concentration in different brain centres, using a PET scanner. The studies were limited because of the radiation dose to the patients. Dr Shaywitz and his colleagues studied 19 right-handed men and 19 right-handed women. They were given a series of nonsense words and asked to check whether they rhymed, but without speaking them out loud.