Study: More Facebook Friends Means Bigger Brain Regions
October 19, 2011

What Does Your Facebook Friends List Say About Your Brain?

New research has found that people with more Facebook friends tend to have bigger brain regions than those with fewer friends, suggesting that using online social networks could be changing our brains.

The researchers at University College London (UCL) found that users with the greatest number of friends on the social network had more gray matter in brain regions linked to social skills. The neuroscientists say the finding could mean that either social networking changes these brain regions, or that people born with these kinds of brains behave differently on such social sites and may have more friends to begin with.

“The exciting question now is whether these structures change over time -- this will help us answer the question of whether the Internet is changing our brains,” said Ryota Kanai of UCL, one of the researchers involved in the study.

The study, published in the journal Proceedings of the Royal Society B Biological Sciences, and funded by Wellcome Trust, examined 3D brain scans of 125 university students at UCL, all of whom were active Facebook users. The four brain areas scanned are known to play a role in memory, emotional responses and social interactions.

The team discovered a strong connection between the number of Facebook friends and the amount of “gray matter” in the amygdala, the right superior temporal sulcus, the left middle temporal gyrus, and the right entorhinal cortex. Gray matter is the layer of brain tissue where mental processing occurs.

The thickness of gray matter in the amygdala was also linked to the number of real-world friends the students had, but in the other three regions, size only appeared to be related to online friends.

The students had an average of 300 online friends, with the most having up to 1,000. Online social interaction have become a major component of social structure, especially in the young, with more than 800 million active users worldwide on Facebook alone.

To substantiate the study results, the team cross-checked their findings in a further group of 40 students.

“Online social networks are massively influential, yet we understand very little about the impact they have on our brains. This has led to a lot of unsupported speculation the Internet is somehow bad for us,” Geraint Rees of UCL told BBC News.

“This shows we can use some of the powerful tools in modern neuroscience to address important questions -- namely, what are the effects of social networks, and online social networks in particular, on my brain,” said Rees.

Heidi Johansen-Berg of the University of Oxford, who was not involved in the research, said the findings were interesting but did not mean Facebook was making people brainier.

“If you got yourself 100 new Facebook friends today then your brain would not be bigger tomorrow,” she told BBC News. “The study cannot tell us whether using the Internet is good or bad for our brains.”

But having more gray matter could lead to us having more friends, as the research suggests. “We have found some interesting brain regions that seem to link to the number of friends we have” in the online social world, but not in the real world, said Kanai.

The right superior temporal sulcus has a role in perception and may be impaired in autism; the left middle temporal gyrus is associated with reading social cues; and the right entorhinal complex is thought to be important in memory and navigation.

Rees, who led the research, said little is understood about the impact of social networks on the brain, which has led to speculation the internet is somehow bad for us.

“Our study will help us begin to understand how our interactions with the world are mediated through social networks,” he said. “This should allow us to start asking intelligent questions about the relationship between the internet and the brain - scientific questions, not political ones.”

“We cannot escape the ubiquity of the internet and its impact on our lives, yet we understand little of its impact on the brain, which we know is plastic and can change over time,” said Dr. John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust.

“This new study illustrates how well-designed investigations can help us begin to understand whether or not our brains are evolving as they adapt to the challenges posed by social media,” said Williams, who was not involved in the study.

The researchers said while their work did not directly answer questions about how digital technology could be responsible for the increase in the number of people diagnosed with autistic spectrum disorders, it did show how future studies could be designed to do so.

That assessment was in response to Baroness Susan Greenfield, former director of the Royal Institution, who made the controversial suggestion in August.

“A key question for debate in contemporary societies with online social networks is do people use them in the same way or are they enabling a completely different type of communication and interaction that was never before possible?” Rees told The Guardian. “People get worried about whether that is in some way affecting or changing our brains or the ways we interact with the world.”

“What we´re attempting to do is get an empirical handle using the types of data we can generate to try and start that process rolling,” said Rees. He added that future brain scan studies looking at changes to brain structures over time might help unravel whether the brain changes were a cause or effect of having more online social links.

Researchers in previous studies have demonstrated a correlation between the volume of the neocortex -- the part of the brain largely responsible for higher functions like language and thought -- and social group size in different primate species.

Anthropologist Professor Robin Dunbar, of the University of Oxford, has proposed that the number of people with whom humans can maintain stable relationships is limited by the size of our neocortex to an average of around 150. The concept later became known as “Dunbar´s number.”

He led research showing connections between the size of real-world social groups and the density of gray matter in similar brain regions to those identified in the new study.

“It has been demonstrated that across primate species there is a relationship between neocortex volume generally and frontal neocortex volume in particular and social group size,” Dunbar told The Guardian. “This work and our study are some of the first attempts to show this holds within species as well as between species.”

“The interesting question left unanswered is whether this is set in stone and those bits of your brain are hard-wired and determined by your genes, or whether if you bring people up in the right kind of social environment, those bits of the brain grow and therefore the number of people they can maintain as friends in adulthood increases,” he added. 


On the Net: