From New Scientist:
Your brain undergoes four dramatic periods of change from age 0 to 90
Our brain wiring seems to undergo four major turning points at ages 9, 32, 66 and 83, which could influence our capacity to learn and our risk of certain
The brain has distinct regions that exchange information via white matter tracts – wiry structures made of spindly projections, called axons, that project from neurons, or brain cells. These connections influence our cognition, such as our memory. But it was unknown whether major shifts in this wiring occur throughout life. “No one has combined multiple metrics together to characterise phases of brain wiring,” says Alexa Mousley at the University of Cambridge.
To fill this knowledge gap, Mousley and her colleagues analysed MRI brain scans from around 3800 people in the UK and US, who were mostly white, and ranged in age from newborns to 90. These scans were previously taken as part of various brain imaging projects, most of which excluded people with neurodegenerative or mental health conditions.
The researchers found that among people who reach 90, the brain’s wiring has generally undergone five main phases, separated by four key turning points.
In the first phase, which occurs between birth and 9 years old, white matter tracts between brain regions seem to become longer, or more convoluted, making them less efficient. “It takes longer for information to pass between regions,” says Mousley.
This could be because our brain is packed with lots of connections as infants, but as we grow and experience things, the ones we don’t use are gradually pruned away. The brain seems to prioritise making a broad range of connections that are useful for things like learning to play the piano, at the cost of them being less efficient, says Mousley.
But during the second phase, between 9 and 32 years old, this pattern seems to flip, which is potentially driven by the onset of puberty and its hormonal changes influencing brain development, says Mousley. “Suddenly, the brain is increasing the efficiency of the connections – they become shorter, so information gets from one place to another more quickly.” This may support the development of skills like planning and decision-making, and improvements in cognitive performance, such as working memory, says Mousley.
Read full story: Your brain undergoes four dramatic periods of change from age 0 to 90
Open access paper:
Topological turning points across the human lifespan
https://www.nature.com/articles/s41467-025-65974-8
