New brain networks come ‘online’ during adolescence, allowing teenagers to develop more complex adult social skills, but potentially putting them at increased risk of mental illness, according to new research.
Brain networks come ‘online’ during adolescence to prepare teenagers for adult life
Adolescence is a time of major change in life, with increasing social and cognitive skills and independence, but also increased risk of mental illness. While it is clear that these changes in the mind must reflect developmental changes in the brain, it has been unclear how exactly the function of the human brain matures as people grow up from children to young adults.
A team based in the University of Cambridge and University College London has published a major new research study that helps us understand more clearly the development of the adolescent brain.
The study, published in the Proceedings of the National Academy of Sciences (PNAS), collected functional magnetic resonance imaging (fMRI) data on brain activity from 298 healthy young people, aged 14-25 years, each scanned on one to three occasions about 6 to 12 months apart. In each scanning session, the participants lay quietly in the scanner so that the researchers could analyse the pattern of connections between different brain regions while the brain was in a resting state.
The team discovered that the functional connectivity of the human brain – in other words, how different regions of the brain ‘talk’ to each other – changes in two main ways during adolescence.
The brain regions that are important for vision, movement, and other basic faculties were strongly connected at the age of 14 and became even more strongly connected by the age of 25. This was called a ‘conservative’ pattern of change, as areas of the brain that were rich in connections at the start of adolescence become even richer during the transition to adulthood.
However, the brain regions that are important for more advanced social skills, such as being able to imagine how someone else is thinking or feeling (so-called theory of mind), showed a very different pattern of change. In these regions, connections were redistributed over the course of adolescence: connections that were initially weak became stronger, and connections that were initially strong became weaker. This was called a ‘disruptive’ pattern of change, as areas that were poor in their connections became richer, and areas that were rich became poorer.
By comparing the fMRI results to other data on the brain, the researchers found that the network of regions that showed the disruptive pattern of change during adolescence had high levels of metabolic activity typically associated with active re-modelling of connections between nerve cells.
Image: Brain development during adolescence: red brain regions belong to the “conservative” pattern of adolescent development, while the blue brain regions belong to the “disruptive” pattern
Credit: Frantisek Vasa
Reproduced courtesy of the University of Cambridge
The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Stephen Toope, is also the President of the Cambridge Network.