Do bigger social networks mean bigger Brain?
A study presented on Tuesday in San Diego suggests that our social interactions can change our brain structure.
Oxford University neuroscientist and study researcher MaryAnn Noonan said that the group was ‘interested in how your brain is able to allow you to navigate in complex social environments.
‘Basically, how many friends can your brain handle?’
Studies with monkeys revealed that the parts of their brain that process faces and help predict the intentions of others were larger in those who lived in bigger social groups than those who lived in smaller groups.
To see if the same phenomenon occurred with humans, Noonan and her colleagues at McGill University, Canada studied the brains and social activity of 18 participants. To determine the size of the participants’ social networks, the scientists asked how many social interactions the participants experienced in the past month.
After scanning the social networks and the areas in the brain that dealt with ‘mentalisation’ (our ability to assign mental states, thoughts and beliefs to other people), the researchers concluded that the target brain areas of those with larger social networks were more connected and enlarged.
Noonan explained ‘These different brain regions are all singing different songs. Networked areas are all singing the same song, and when they’re connected better, they’re singing more harmoniously with each other.’
White-matter pathways (nerve fibres that connected the regions of the brain) were also tested for their size. Again, they concluded that the pathways were better connected in people with larger social circles. Noonan said ‘The nerves were more like a Los Angeles freeway than a country road.’
Despite the relationship between the size of the social circle and the brain, scientists do not yet know whether the social interaction caused the brain to change or if the brain was innately ‘social.’ Noonan said more studies need to be made to establish this.
She added that the socially adept may also have brain regions which were smaller than others. ‘If you’re spending a lot of time in social environments using social skills and your brain’s changing, maybe you’re not learning to juggle in your free time or becoming proficient at the piano.
‘The brain is just changing and optimising to reflect your needs, and if that is thriving within a complex social environment, that is what your brain is reflecting.’