Brain networks show increased connectivity
from front to back and within one hemisphere in males, suggesting their brains are structured to facilitate connectivity between perception and coordinated action (upper)
from left to right and between hemispheres in females, suggesting that they facilitate communication between the analytical and intuition (lower).
Brain Connectivity Study Reveals Striking Differences Between Men and Women
Penn Medicine Brain Imaging Study Helps Explain Different Cognitive Strengths in Men and Women
Perelman School of Medicine at the University of Pennsylvania
http://www.uphs.upenn.edu/news/news_releases/2013/12/verma/
A new brain connectivity study from Penn Medicine published today in the Proceedings of the National Academy of Sciences found striking differences in the neural wiring of men and women that’s lending credence to some commonly-held beliefs about their behavior.
In one of the largest studies looking at the “connectomes” of the sexes, Ragini Verma, PhD, an associate professor in the department of Radiology at the Perelman School of Medicine at the University of Pennsylvania, and colleagues found greater neural connectivity from front to back and within one hemisphere in males, suggesting their brains are structured to facilitate connectivity between perception and coordinated action. In contrast, in females, the wiring goes between the left and right hemispheres, suggesting that they facilitate communication between the analytical and intuition.
“These maps show us a stark difference–and complementarity–in the architecture of the human brain that helps provide a potential neural basis as to why men excel at certain tasks, and women at others,” said Verma.
For instance, on average, men are more likely better at learning and performing a single task at hand, like cycling or navigating directions, whereas women have superior memory and social cognition skills, making them more equipped for multitasking and creating solutions that work for a group. They have a mentalistic approach, so to speak.
Past studies have shown sex differences in the brain, but the neural wiring connecting regions across the whole brain that have been tied to such cognitive skills has never been fully shown in a large population.
In the study, Verma and colleagues, including co-authors Ruben C. Gur, PhD, a professor of psychology in the department of Psychiatry, and Raquel E. Gur, MD, PhD, professor of Psychiatry, Neurology and Radiology, investigated the gender-specific differences in brain connectivity during the course of development in 949 individuals (521 females and 428 males) aged 8 to 22 years using diffusion tensor imaging (DTI). DTI is water-based imaging technique that can trace and highlight the fiber pathways connecting the different regions of the brain, laying the foundation for a structural connectome or network of the whole brain.
This sample of youths was studied as part of the Philadelphia Neurodevelopmental Cohort, a National Institute of Mental Health-funded collaboration between the University of Pennsylvania Brain Behavior Laboratory and the Center for Applied Genomics at the Children’s Hospital of Philadelphia.
The brain is a roadmap of neural pathways linking many networks that help us process information and react accordingly, with behavior controlled by several of these sub-networks working in conjunction.
In the study, the researchers found that females displayed greater connectivity in the supratentorial region, which contains the cerebrum, the largest part of the brain, between the left and right hemispheres. Males, on the other hand, displayed greater connectivity within each hemisphere.
By contrast, the opposite prevailed in the cerebellum, the part of the brain that plays a major role in motor control, where males displayed greater inter-hemispheric connectivity and females displayed greater intra-hemispheric connectivity.
These connections likely give men an efficient system for coordinated action, where the cerebellum and cortex participate in bridging between perceptual experiences in the back of the brain, and action, in the front of the brain, according to the authors. The female connections likely facilitate integration of the analytic and sequential processing modes of the left hemisphere with the spatial, intuitive information processing modes of the right side.
The authors observed only a few gender differences in the connectivity in children younger than 13 years, but the differences were more pronounced in adolescents aged 14 to 17 years and young adults older than 17.
The findings were also consistent with a Penn behavior study, of which this imaging study was a subset of, that demonstrated pronounced sexual differences. Females outperformed males on attention, word and face memory, and social cognition tests. Males performed better on spatial processing and sensorimotor speed. Those differences were most pronounced in the 12 to 14 age range.
“It’s quite striking how complementary the brains of women and men really are,” said Dr. Ruben Gur. “Detailed connectome maps of the brain will not only help us better understand the differences between how men and women think, but it will also give us more insight into the roots of neuropsychiatric disorders, which are often sex related.”
Next steps are to quantify how an individual’s neural connections are different from the population; identify which neural connections are gender specific and common in both; and to see if findings from functional magnetic resonance imaging (fMRI) studies fall in line with the connectome data.
Co-authors of the study include Madhura Ingalhalikar, Alex Smith, Drew Parker, Theodore D. Satterthwaite, Mark A. Elliott, Kosha Ruparel, and Hakon Hakonarson of the Section of Biomedical Image Analysis and the Center for Biomedical Image Computing and Analytics.
How Men’s Brains Are Wired Differently than Women’s
Male brains have more connections within hemispheres to optimize motor skills, whereas female brains are more connected between hemispheres to combine analytical and intuitive thinking
by Tanya Lewis
Scientific American
http://www.scientificamerican.com/article/how-mens-brains-are-wired-differently-than-women/
Men aren’t from Mars and women aren’t from Venus, but their brains really are wired differently, a new study suggests.
The research, which involved imaging the brains of nearly 1,000 adolescents, found that male brains had more connections within hemispheres, whereas female brains were more connected between hemispheres. The results, which apply to the population as a whole and not individuals, suggest that male brains may be optimized for motor skills, and female brains may be optimized for combining analytical and intuitive thinking.
“On average, men connect front to back [parts of the brain] more strongly than women,” whereas “women have stronger connections left to right,” said study leader Ragini Verma, an associate professor of radiology at the University of Pennsylvania medical school. But Verma cautioned against making sweeping generalizations about men and women based on the results.
Previous studies have found behavioral differences between men and women. For example, women may have better verbal memory and social cognition, whereas men may have better motor and spatial skills, on average. Brain imaging studies have shown that women have a higher percentage of gray matter, the computational tissue of the brain, while men have a higher percentage of white matter, the connective cables of the brain. But few studies have shown that men’s and women’s brains are connected differently.
In the study, researchers scanned the brains of 949 young people ages 8 to 22 (428 males and 521 females), using a form of magnetic resonance imaging (MRI) known as diffusion tensor imaging, which maps the diffusion of water molecules within brain tissue. The researchers analyzed the participants as a single group, and as three separate groups split up by age.
As a whole, the young men had stronger connections within cerebral hemispheres while the young women had stronger connections between hemispheres, the study, detailed today (Dec. 2) in the journal Proceedings of the National Academy of Sciences, found. However, the cerebellum, a part of the brain below the cerebrum that plays a role in coordinating muscle movement, showed the opposite pattern, with males having stronger connections between hemispheres.
Roughly speaking, the back of the brain handles perception and the front of the brain handles action; the left hemisphere of the brain is the seat of logical thinking, while the right side of the brain begets intuitive thinking. The findings lend support to the view that males may excel at motor skills, while women may be better at integrating analysis and intuitive thinking.
“It is fascinating that we can see some of functional differences in men and women structurally,” Verma told LiveScience. However, the results do not apply to individual men and women, she said. “Every individual could have part of both men and women in them,” she said, referring to the connectivity patterns her team observed.
When the researchers compared the young people by age group, they saw the most pronounced brain differences among adolescents (13.4 to 17 years old), suggesting the sexes begin to diverge in the teen years. Males and females showed the greatest differences in inter-hemisphere brain connectivity during this time, with females having more connections between hemispheres primarily in the frontal lobe. These differences got smaller with age, with older females showing more widely distributed connections throughout the brain rather than just in the frontal lobe.
Currently, scientists can’t quantify how much an individual has male- or female-like patterns of brain connectivity. Another lingering question is whether the structural differences result in differences in brain function, or whether differences in function result in structural changes.
The findings could also help scientists understand why certain diseases, such as autism, are more prevalent in males, Verma said.
That’s really thiinkng out of the box. Thanks!