Mannenbrein heeft heel andere bedrading dan het vrouwenbrein
Scientias. Geschreven op 3 december 2013 door Caroline KraaijvangerWetenschappers hebben ontdekt dat de verbindingen in het brein van een vrouw heel anders zijn dan die in het brein van een man. En die verschillen verklaren een hoop als het gaat om 'typisch' mannelijk of vrouwelijk gedrag. Onderzoekers van de universiteit van Pennsylvania bestudeerden de hersenen van 949 proefpersonen (vanaf acht jaar oud) en keken hoe deze hersenen zich door de jaren heen ontwikkelden. Ze richtten zich daarbij met name op de verbindingen in het brein.
Verschillen
De verbindingen in een vrouwenbrein zijn heel anders dan die in een mannenbrein. Maar die verschillen zijn niet het hele leven door even groot. Wanneer mensen tussen de twaalf en veertien jaar oud zijn, zijn de verschillen het grootst.
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het verschil in verbindingen tussen ♂ en ♀ hersenen in de ♂ hersenen tussen voor en achter (blauw) in de ♀ hersenen tussen links en rechts (rood) |
In de kleine hersenen was het juist omgekeerd: mannen hadden betere verbindingen tussen de twee helften van de kleine hersenen, terwijl de vrouwen juist betere verbindingen binnen die helften hadden.
De verschillen tussen mannen en vrouwen verklaren waarom mannen en vrouwen doorgaans elk hun talenten hebben.
Zo stellen de verbindingen in het vrouwenbrein de vrouw in staat om te multitasken en oplossingen te bedenken die een groep ten goede komen. Ook heeft de vrouw dankzij die verbindingen doorgaans een uitstekend geheugen en is ze een intuïtieve denker.
De verbindingen in het mannenbrein geven de mannen een voorsprong als het gaat om motorisch leren (bijvoorbeeld leren fietsen). Ook kunnen mannen sneller actie ondernemen als er iets gebeuren moet, aangezien de verbindingen tussen het achterste deel van het brein (perceptie, gewaarwording) en het voorste deel van het brein (actie, handelen) sterker zijn. Ook is hun ruimtelijk inzicht beter.
Bronmateriaal:
"Brain Connectivity Study Reveals Striking Differences Between Men and Women" - upenn.edu
Perelman School of Medicine at the University of Pennsylvania
December 2, 2013
Brain Connectivity Study Reveals Striking Differences Between Men and Women
Penn Medicine Brain Imaging Study Helps Explain Different Cognitive Strengths in Men and Women
Philadelphia - A new brain connectivity study from Penn Medicine published today in the Proceedings of 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.
Brain networks show increased connectivity from front to back and within one hemisphere in males (upper) and left to right in females (lower). Credit: Ragini Verma, PhD, Proceedings of National Academy of Sciences
University of Pennsylvania Health System
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.
This study was funded by in part by the National Institutes of Mental Health: MH089983, MH089924, MH079938, and MH092862.
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