A new study out of Penn Medicine dealing with brain connectivity says that there really are differences in how male and female brains are wired, seeming to confirm age-old ideas about how men and women behave in very different ways.
In the study, which was conducted by Dr. Ragini Verma, an associate professor in the department of Radiology at the Perelman School of Medicine at the University of Pennsylvania, Verma and her team looked at what is known as connectomes in both genders. Experts say that connectomes can be thought of as sort of a wiring diagram for how the brain’s component parts link together.
What they found when they examined male and female connectomes was that there was more neural connectivity from front to back and within one hemisphere in males. This suggested, they say, that male’s brains are wired to enhance the connection between perception and coordinated action. Female’s brains, however, are wired with more connectivity between the right and left hemisphere, which suggests that there is better communication between the analytical and the intuitive parts of the brain.
Verma says that this difference in brain structure helps explain why men and women appear to each be better at different types of activities. And, in fact, these differences are complementary of each other.
The examples that the study authors gave of such activities include the fact that males appear to be better and learning and performing a single task, such as following directions, while females are far better at memory and social cognition, making them best at tasks while require multitasking and finding group solutions.
Although previous studies have demonstrated such differences in male and female brains, this is one of the first larger studies to show these variations in neural wiring.
In order to carry out the study into gender-related differences in brain connectivity, Verma and her team of researchers studied 949 people (521 females and 428 males) between the ages of eight and 22 years. They used a water-based imaging technique called diffusion tensor imaging (DTI) to trace and highlight the fiber pathways which connect the various regions of the brain, building up a foundation for the structural network of the entire brain.
The sample of young people used for study was part of the Philadelphia Neurodevelopment Cohort, a coordinated effort between the Center for Applied Genomics at the Children’s Hospital of Philadelphia and the University of Pennsylvania Brain Behavior Laboratory. The study was funded by the National Institute of Mental Health.
The researchers found that girls and women showed greater connectivity in a region called the supratentorial region. This area of the brain contains the cerebrum, which is the largest part of the brain, and is located between the right and left hemispheres. Boys and men, however, had greater connectivity within each hemisphere.
In the cerebellum, which is the part of the brain involved in motor control, things were different, however. In males, there was more connectivity between hemispheres, while females displayed more connectivity within each hemisphere.
Most likely, the authors says, these type of connections in males, which bridge the cerebellum (involves perception) and the front of the brain (involves action), make men better at coordinated action. Women, on the other hand, having stronger connections between the left hemisphere (involves analytic and sequential processing) and the right hemisphere (involves spatial and intuitive processing) tend to be better at integrating these functions.
Rather interestingly, there were fewer gender differences in children younger than 13, with the differences becoming stronger as they grew into adolescence and adulthood.
In a related behavior study, it was found that females did better than males in tests of attention, face and word memory and social cognition. Males, however, outperformed females in spatial processing and sensorimotor speed.
According to Dr. Ruben Gur, a co-author on the study, it was “quite striking how complementary the brains of women and men really are.” By making detailed connectome maps of the brain, he says, it will help us better understand not only behavioral difference between the genders, but also where gender-related differences in neurological disorders spring from.
The next step in the process, the researchers say is discern how an individual person’s neural connections are different from the population at large, as well as determining what connections are specific to a person’s gender and which are common to all people. In addition, they would like to see if their connectome data match up with findings from functional magnetic resonance imaging (fMRI). This type of imaging study seeks to measure brain activity by measuring changes in blood flow and oxygenation in response to neural activity.
The study was published in the December 2, 2013 issue of the Proceedings of National Academy of Sciences.
By Nancy Schimelpfening