Adolescence lasts into your 30s, and other surprises about the brain

THE human brain has four distinct turning points where its structure changes, according to a study published in the journal Nature Communications, demonstrating that brain development is not as linear as you might think.

- MAGGIE PENMAN

“It's easy to fall into this belief that there's a ‘good’ or ‘bad’ way for a brain to be structured,” said lead study author Alexa Mousley at the University of Cambridge. “And that’s not really the case. What this study is emphasising is the brain is expected to be doing something different at different ages.”

In the new study, Mousley and colleagues looked at about 4000 scans from healthy people ages 0 to 90 and analysed their brains. They found four major times when the brain underwent developmental changes, around ages nine, 32, 66 and 83, dividing the lifespan into five distinct phases.

Mousley and her coauthors identified five epochs during which the brain is wired in different ways.

Childhood

From infancy to 9 years old, the brain is busy. There is a lot of consolidation of neural connections happening, competitive elimination of synapses and rapid increases in gray and white matter. But interestingly the brain is becoming less efficient during this time — so it takes longer for information to get from one region of the brain to another. The researchers don’t fully understand why this would be the pattern, but they have some theories.

Whatever the reason for the brain becoming less efficient during childhood, itis a time when a lot of learning happens — language, motor skills, speech — and there is likely a reason that the brain is structured the way that it is during this period.