Neuroscientists generally agree that there are certain differences between the brains of men and women, but the extent of those differences and what they mean remain controversial.
One of these areas of controversy is visuospatial processing - it seems likely that, at least in some ways, men and women really do see the world in different ways.
Visuospatial processing refers to the perception of objects in the world around us and how they behave in space.
In a recently published article, researcher Amy Clements-Stephens of Hopkins and the Kennedy Krieger Institute concluded that there were, in fact, subtle differences in the visuospatial abilities of men and women.
They found that men and women did not have substantial differences in skill, but surprisingly they used different parts of the brain to perform the same task.
We use visuospatial processing whenever our eyes are open, but for a common visuospatial task, think about Tetris. In this game, you need to change each descending shape to fit with the existing shapes. In other words, you are aware of the object's geometry as you rotate the shape until it fits.
In previous visuospatial studies, a task known as mental rotation has been shown to have a difference between males and females. Similar to Tetris, this task involves looking at an obscure orientation of an object and trying to match it with the original view of the object.
If you are presented with a picture of a chair, you should have no problem recognizing it.
Yet if you are shown an image of an upside-down chair that has been rotated, you might have a harder time. Previous studies have found that men perform better than women in these types of tasks.
Clements-Stephens and her colleagues tested several types of mental rotation tasks.
They believed that the mental rotation task involves higher cognitive processes and might not directly show a comparison of gender-specific visuospatial skills.
They chose a much simpler task that involved deciding if two sets of lines were oriented in the same or in different direction.
This research team also wanted to find out if sex differences in visuospatial skills started in childhood. This would provide insight into how the brains of each sex mature over a developmental time period.
They selected 32 children between the ages of 7 and 15 to participate in their study.
In order to measure any brain differences, they used functional magnetic resonance imagFAKEimg (fMRI) machines to record which areas of the brain were activated during each of the tasks. The children would be in these machines while looking at the line orientation task.
The fMRI would measure which brain regions received the most blood flow, an indicator of brain activity, during the task.
They did not find any difference between males and females in the accuracy of completing the task. Both groups had similar response times. This shows that males and females perform equally well on this task.
Yet, this does not mean that males and females perform in the same way on the task.
Clements-Stephens and colleagues found that different brain areas were active across genders, as well as across different ages. Though many brain regions were used in both sexes, certain areas were more active in males.
On the other hand, when older and younger participants were compared, there were several differences in the brain regions that were activated.
As the boys grew older, they had more activity localized to the left hemisphere. The girls, as age increased, showed more activity across both hemispheres.
The regions that were more active in males corresponded to movement planning and spatial memory. Clements-Stephens and her team concluded that males use a basic visuomotor network in responding to spatial tasks, while females use spatial attention and memory to complete the tasks. Also, males and females develop these skills by using different brain regions.
These findings imply that, although males and females are able to do the same sorts of visuospatial cognitive tasks, they may nevertheless perceive the world in different ways.
Though both groups performed equally well at this task, they used different neural networks to do so.
This work leads to questions of what other processes might behave in a similar manner. If mental rotation uses different pathways in men and women, perhaps other visuospatial skills do too -- maybe even causing real differences in visual perception between the sexes.
Although these studies do not in any way imply that one gender is more intelligent than the other, further studies into gender differences of the brain could lead to constructive changes in the the way we work and learn, such that everyone can use their brains to their full potential.
