There’s truth to the “manchild” trope.
UK researchers have discovered that adulthood starts much later than we thought, per an eye-opening study published in the journal Nature.
“Based purely on neural architecture, we found that adolescent-like changes in brain structure end around the early thirties,” wrote the researchers, who hailed from the University of Cambridge.
These extended wonder years are just one of five major epochs in brain structure during an average human life, divided into four pivotal “turning points” between birth and death.
Lead author Dr. Alexa Mousley told the BBC that the brain constantly changes across one’s lifespan, “strengthening and weakening connections” as the mind reconfigures.
She pointed out that this was the first “first to identify major phases of brain wiring across a human lifespan,” per a release by the university.
To shed light on the phases of the brain, the researchers compared the neurological activity of 3,802 people between zero and ninety years old.
They specifically looked at the data from MRI scans, which “map neural connections by tracking how water molecules move through brain tissue,” per a release by the university.
Phase one –the “childhood phase” — lasts until age nine, per the study. During this window, the brain’s wealth of synapses – the connectors between neurons – “are whittled down, with the more active ones surviving.”
By the first pivotal point at nine years old, the brain is undergoing a major boost in cognitive capacity, but also a heightened risk of mental health disorders.
This is when it enters stage two, the adolescent phase, which lasts from 9 until the late 30s, like a neurological fountain of youth.
But this is not a sign of arrested development. This era is marked by an increase in white matter — the high-speed wiring that connects different regions so they can communicate.
As a result, the structure of the brain’s communication networks becomes increasingly refined, causing more neural efficiency and “enhanced cognitive performance,” per the release.
This brain boost peaks at age 32, which is when we see the “most directional changes in wiring and the largest overall shift in trajectory, compared to all the other turning points,” per Mousley.
The next stage is the adulthood era — the longest of the five epochs. This pivotal point when the architecture of the mind stabilizes with no major changes in personality or cognitive abilities for 30 years.
That lasts until age 66, when the brain enters the early aging phase, marked by a “gradual reorganization of brain networks” and “reduced connectivity” caused by white matter degeneration, Mousley said.
“This is an age when people face increased risk for a variety of health conditions that can affect the brain, such as hypertension,” she said.
The fifth and final stage is the late aging brain phase, which occurs circa age 83. While researchers noted that data for this era is “limited,” they said that “connectivity declines even further” during this epoch, “with increased reliance on certain regions.”
Of course, they’re not just mapping the progression of the mind for curiosity’s sake.
Duncan Astle, a professor of Neuroinformatics at Cambridge, pointed out that many mental and “neurological conditions are linked to the way the brain is wired,” thereby allowing us to “predict difficulties with attention, language, memory, and a whole host of different behaviors.”
“Understanding that the brain’s structural journey is not a question of steady progression, but rather one of a few major turning points, will help us identify when and how its wiring is vulnerable to disruption,” he said.