Do babies have a ‘Social Brain’?

The capacity to engage and communicate in a social world, is one defining the characteristics of the human species. Adults have special areas of the brain, sometimes referred to as the ‘social brain’, which respond to different human actions, such as eye, mouth and hand movements. We interpret how sociable and communicative these movements are. One question researchers are seeking to answer is : Do babies respond to such sociable dynamic movements? Do they have a similarly sophisticated brain, specialist for responding to such actions?

This is important because paying attention to this kind of social information is fundamental to a child’s development, enabling them to find out information about the world around them, engaging in our social world. Learning more about how a typical brain develops can also help us to see when and how things may go wrong during the development, giving us a better understanding of many development disorders such as autism.

One of the greatest challenges faced by researchers when trying to answer such questions, is finding ways to understand what babies are thinking, as we cannot just ask them!

At the Babylon and Birbeck, University of London, they use a variety of techniques to obtain answers from babies. One such technique developed is known as functional Near InfaRed Spectroscopy, or ‘fNIRS’. This measures naturally occurring brain activity by looking at change in oxygen levels in the brain. Where areas of our brains are more active, for example because they are responding to what we are seeing or hearing, they use up more oxygen, and the colour of the blood in our brain changes.To carry out the test, babies wear a soft hat, containing weak near infrared lights. This produces results similar to shining a torch, or as any naturally occurring light in our environment. The lights change colour according to the colour of the blood; these changes are measured at the same time, giving us a map of the naturally occurring brain activity. By looking at the different oxygen levels on the map, we can determine which areas of the brain are responding to different stimuli.

In one of our studies, five month old babies, were shown videos of actors moving their hand, eyes or mouth, whilst wearing the fNIRS hat. Although it is too early to draw firm conclusions, preliminary results from the study suggest that babies are indeed able to detect subtile differences in the actions of the actors, showing responses in distinct areas of the brain that correspond with the socially specialised areas of the brain seen in adults. Infants do, therefore, appear to be more sensitive to certain socially relevant movements from an early age.  These brain responses appear to be occurring in the areas that are thought to make up the so-called ‘social brain’ network in adults.

Further research will establish whether babies are sensitive to such social cues from the moments they are born, and whilst in the womb even.

It will help our understanding into whether it is a skill which gradually develops over the first few moths of life.

Until next time,