Scientists have found a direct link between the number of ‘Facebook
friends’ a person has and the size of particular brain regions.
In a study
published today, researchers at UCL also showed
that the more Facebook friends a person has, the more ‘real-world’ friends they
are likely to have.
researchers are keen to stress that they have found a correlation and not a
cause: in other words, it is not possible from the data to say whether having
more Facebook friends makes the regions of the brain larger or whether some people
are ‘hard-wired’ to have more friends.
The social networking site Facebook has more than 800
million active users worldwide. Nearly 30 million of these are believed to be
in the UK.
The site allows people to keep in touch online with a network of friends. The
size of these networks varies considerably, with some users having only a
handful of online friends whilst others have over a thousand – however, whether
this variability is reflected in the size of real-world social networks has not
Professor Geraint Rees, a Wellcome Trust Senior Clinical Research
Fellow at UCL, said: “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.
“Our study will help us begin to understand how our interactions with the
world are mediated through social networks. This should allow us to start
asking intelligent questions about the relationship between the internet and
the brain – scientific questions, not political ones.”
Professor Rees and colleagues at the UCL Institute of
Cognitive Neuroscience and the Wellcome Trust Centre for Neuroimaging studied
brain scans of 125 university students – all active Facebook users – and
compared them against the size of the students’ network of friends, both online
and in the real world. Their findings, which they replicated in a further group
of 40 students, are published today in the journal Proceedings of
the Royal Society B.
Professor Rees and colleagues found a strong connection
between the number of Facebook friends an individual had and the amount of grey
matter in several regions of the brain. Grey matter is the brain tissue where
the processing is done. One of these regions was the amygdala, a region
associated with processing memory and emotional responses. A study published
recently showed that the volume of grey matter in this area is larger in people
with a larger network of real world friends – today’s study shows that the same
is true for people with a larger network of online friends.
The size of three other regions – the right superior
temporal sulcus, the left middle temporal gyrus and the right entorhinal cortex
– also correlated with online social networks, but did not appear to correlate
with real-world networks.
The superior temporal sulcus plays a role in our ability to
perceive a moving object as biological, and structural defects in this region
have been identified in some children with autism. The entorhinal cortex,
meanwhile, has been linked to memory and navigation – including navigating
through online social networks. Finally, the middle temporal gyrus has been
shown to activate in response to the gaze of others and so is implicated in
perception of social cues.
Dr Ryota Kanai, first author of the study added: “We have
found some interesting brain regions that seem to link to the number of friends
we have – both ‘real’ and ‘virtual’. 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.”
As well as examining brain structure, the researchers also examined
whether there was a link between the size of a person’s online network of
friends and their real world network. Previous studies have looked at this, but
only in relatively small sample sizes.
The UCL researchers asked their volunteers questions such as
‘How many people would send a text message to marking a celebratory event (e.g.
Birthday, new job, etc.)?’, ‘What is the total number of friends in your
phonebook?’ and ‘How many friends have you kept from school and university that
you could have a friendly conversation with now?’ The responses suggest that
the size of their online networks also related to the size of their real world
“Our findings support the idea that most Facebook users use
the site to support their existing social relationships, maintaining or
reinforcing these friendships, rather than just creating networks of entirely
new, virtual friends,” adds Professor Rees.
brain’ is one of the Wellcome Trust’s key strategic challenges. At the Wellcome
Trust Centre for Neuroimaging, clinicians and scientists study higher cognitive
function to understand how thought and perception arise from brain activity,
and how such processes break down in neurological and psychiatric disease.
Commenting on the study, Dr John Williams, Head of Neuroscience and
Mental Health at the Wellcome Trust, said: “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. 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.”
Image: My Facebook Friends by enda_001 on Flickr. Some rights reserved
Source: Wellcome Trust
Professor Geraint Rees
UCL Institute of Cognitive Neuroscience
Proceedings of the Royal Society B