April 11, 2007

Brain Study Finds Male-Female Differences in Eye-Hand Co-Ordination


OTTAWA (CP) - Women use more of their brains than men when it comes to driving a car, using a computer mouse or performing other visually guided actions, says a new study that suggests stroke victims should have different rehabilitation programs depending on their gender.

The way your brain "fires" in the split second before doing tasks that require eye-hand co-ordination depends on whether you're a man or a woman, says Lauren Sergio, a York University professor and co-author of the study.

The study found that for females, areas in both the left and right sides of the brain were active during eye-hand co-ordination experiments. That occurred for men only when they were planning their most complex task: moving a cursor on a screen in the opposite direction to the one expected, using a joystick.

"We found that in females, there were three major brain areas involved in visually guided movement and they showed activity on both sides of the brain in most of the exercises in the study," Sergio said in an interview.

"In contrast, male brains lit up on both sides only for the most complex exercise."

The findings, published in February in the European Journal of Neuroscience, could have implications for the way stroke victims are rehabilitated, said Sergio, a kinesiologist who studies the mechanics of body movements.

"If the stroke is only on one side of the brain, a woman may have rehabilitation options that the man may have more trouble with because the woman may be able to perform tasks using the other side of her brain, which is used to being fired up," Sergio said.

Health professionals should consider gender when designing rehabilitation programs for stroke victims, she said.

"We also need to recognize that men may have more trouble with rehabilitation, and may need to be checked more carefully before they resume everyday activities such as driving."

The research focused on what happens in the brain when what the eye sees is disconnected from what the hand is doing. An example is looking at a computer screen but moving a mouse that is off to the side.

The brains of study participants were scanned by an MRI machine as they were given a series of increasingly complex tasks. The machine monitored brain activity up to the moment when movement started.

Dr. Antoine Hakim, CEO and scientific director of the Canadian Stroke Network, cautioned that gender is only one factor that should be considered in stroke rehabilitation.

"The reality is that when a patient suffers a stroke, so many characteristics of both the stroke itself and the individual become important determinants of how well they recover," he said.

A victim's education, family background and social environment are all considered along with gender when designing stroke rehabilitation programs. The most important factor in stroke recovery is the determination of the patient to get better, Hakim said.

"Does the patient say, 'I'm going to beat this sucker?' Or does he or she sense that they'll never get better? How do I take attitude and convert it into proteins and new stem cells and new recovery pathways in the brain? These are the million-dollar questions."

Hakim says Sergio's conclusions are important because they confirm what rehabilitation workers have suspected for years: that men and women's brains work differently and that gender plays a role in stroke rehabilitation programs.

"The brains of males and females are different," he says, "So let's celebrate."