Facebook may not be keeping the activity of some of your brain regions private, but can it increase the size of your brain?

A recent study has discovered that the number of Facebook friends you have is consistent with the size of certain brain regions, which are associated with creating memories of names and faces as well as how people fare in social interactions.

Other regions were highlighted when researchers compared brain sizes in relation to real-life or offline social networks, implying that Web and real-world interactions could be using different sets of social skills.

In a press conference Monday, study researcher Geraint Rees of the University College London said social networks are not exclusive to the Web nor to traditional social groups.

"Social networks exist in many forms - in the real world, in cyberspace and in many other forms... They are a particular aspect of human behaviour that surrounds and affects many aspects of how we live our daily lives."

Using magnetic resonance imaging, researchers explored the brains of 125 university students and compared the sizes of various regions with each participant's online and actual friends. This group of students had an average of 300 friends, and the one with the most Facebook friends has 1,000 in their network. The study's findings were cross-checked with a further group of 40 students.

The study showed that people who had high numbers of Facebook friends also had larger brain regions, which were associated with interpretation of social gestures (superior temporal sulcus and the middle temporal gyrus), pairing of names and faces (entorhinal cortex), and recognition of emotions in facial expressions (amygdalae).

The researchers found a different pattern when they compared the brain region sizes with the size of the students' real-life social networks.

The size of amygdalae in people who had large real-life social networks is consistent in size, but the sulcus, gyrus and cortex among actual "loners" and gregarious types did not show any differences.

However, the study could not tell which came first - did large social networks nourished certain brain areas, or do pre-existing larger areas of certain brain regions make one predisposed to having larger social networks?

Noting that the study is rather preliminary in nature, Rees said their findings "give us a way to answer important questions."

"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, also from UCL, one of the researchers involved in the study.

Sam Roberts, a researcher at England's University of Chester, near Liverpool, said the findings are interesting, but it would have been better if the levels of the students' interactions on Facebook were considered.

"You can look at the number of friends people have on Facebook, but to really understand what that means you have to look at what they are doing on Facebook with their friends," Roberts, who wasn't involved in the study, told LiveScience.com.