The adolescent brain: explaining Kevin the Teenager?

Jenifer Burden reports back from the ASE annual conference

For those who work or live with teenagers, Harry Enfield’s portrayal of Kevin the Teenager in his 1990s BBC comedy show may be strangely familiar! This morning delegates at the Association for Science Education annual conference were reacquainted with Kevin’s transformation into a teenager by Professor Sarah-Jayne Blakemore, as the introduction to an enthralling lecture on the development of the adolescent brain, which was hosted by the Nuffield Foundation.

Until the 1970s scientists had concluded that development of the human brain was completed during early childhood. However, research since then to measure the density of synapses in brains of different aged individuals shows that the human frontal lobe continues to develop for many years after this, with the final key period of development taking place during adolescence.

After the onset of puberty the frontal lobe – responsible for executive functions such as planning, multi-tasking and inhibiting inappropriate behaviour – shows a marked fall in synapse density as the result of synaptic pruning. During this process unused synapses in the brain are removed, allowing resources to be focused on those synaptic connections that are contributing to the organism’s survival.

In her book, ‘The Learning Brain: Lessons for Education’, Professor Blakemore describes synaptic pruning as essential for ‘fine-tuning’ of the brain’s functional networks. Perhaps if fine-tuning of cognitive processes in the frontal lobe does not take place until adolescence, then there may be a relationship between these structural changes in the brain, and the difficulties some young people can experience as teenagers? As Professor Blakemore notes, ‘Many young people (in the teenage years) are simply not motivated to learn at school or college. It should be possible to find ways of making learning at this stage of life more rewarding, and brain research might have a role to play in this.’

And far more speculatively, perhaps in future neuroscience could provide teenagers with an explanation for particular behaviour traits their parents find difficult to accommodate!

The National STEM Centre eLibrary holds a number of resources to support the teaching of synapse structure and function, such as materials from the National Learning Network biology collection.

Professor Blakemore is based at the Institute of Cognitive Neuroscience, University College London, where her team is pioneering research into social cognitive development during adolescence. ‘The Learning Brain: Lessons for Education’, written by Sarah-Jayne Blakemore and Uta Frith, was published by Wiley-Blackwell in 2005.

An extract from the book outlining synaptic pruning and its role in social cognitive development is available here.