Answering e-mails and organizing meetings, lunches
or other exciting events in the social calendar is the first task of the day
after crawling out of bed to get a kettle filled and heating. I carry on happy
in the knowledge that I’m exercising my amygdala and keeping its grey matter
density up to snuff.
After that comes the attention to the social
networks: Facebook, Linked-In and Google+, which have a little overlap, but not
very much. Again the fleeting fingers on the keyboard do double duty and
massage my amygdala as they scan through to see what people have been up to.
Of course, other parts of the brain are involved
too. Kanai et al, in Proc. Roy. Soc.
B, chose 125 post-grad students of U C London as lab rats for fMRI studies of
their brain structure (1). Young post-grads are expected to have very active
thumbs servicing large numbers of Facebook friends and so they should be good
candidates to see what all this thumb activity was doing to their brains.
They would also have quite large circles of normal
friends – ‘normal’ in this context means ones that they would go to parties and
get drunk with, like post-grads have been doing for generations. Hence, they
could all be expected to have good plump amygdalas. But what else would also be
plumped up by their Facebook work instead of their notebook work?
Three other areas were seen to have benefitted from
their diligence in increasing their social network size. The areas where their
grey matter had been plumped up in proportion to their number of Facebook
friends were the EC, the right STS, and the Left MTG (2). Sounds good, but what
do these parts do?
The ER is active in organizing memory so when your
number of Facebook friends gets into the hundreds, things need to be well
ordered. It is also the first part to go if Alzheimer’s strikes. So we can see
our fast moving thumbs as a good sign.
The right
STS is associated with our noticing what motion others are carrying out and
processing what that means for us. The left MTG is implicated in our processing
of word-meaning. As many comments are short and somewhat cryptic when posted on
the ‘Walls’ of Facebook, it is not surprising that we are heavily exercising
these parts of the brain which are implicated in social perception.
It would appear that our brain plasticity is well
up to the challenges set by the excitement of wandering around reading the
Walls in Facebook. A ‘ripped brain’ somehow doesn’t sound as desirable as ‘ripped
abs’ though, does it?
- R. Kanai, B. Bahrami, R. Roylance and G. Rees, Proc. Roy. Soc. B (2011). Doi: 10.1098.rspb.20-11.1959
- EC – Entorhinal Cortex; right STS – right superior temporal sulcus; left MTG – left middle temporal gyrus.
