If you scroll through TikTok or Instagram long enough, you’ll inevitably come across the phrase, “Your frontal lobe isn’t fully developed yet,” at some point. It’s become a common neuroscience explanation for bad decisions, like ordering one too many drinks at the bar or texting that ex you swore you’d never text again.
It is true that the frontal lobe It plays a critical role in high-level functions such as planning, decision-making, and judgment. And it’s easy to find comfort in the idea that there is a biological excuse for why we sometimes feel unstable, impulsive, or like a work in progress: the immaturity of the frontal lobe. Life in your 20s and 30s is unpredictable, and clinging to the fact that a lot of things happen because your brain hasn’t finished developing can feel strangely reassuring.
But the idea that the brain, particularly the frontal lobe, stops developing at age 25 is a myth. Like many myths, it has its origin in real scientific findings, but oversimplified. In fact, the latest research suggests that the development of the frontal lobe lasts until the age of 30.
Where does the “25 year myth” come from?
The magic number comes from brain imaging studies conducted in the late 1990s and early 2000s. a 1999 studyresearchers tracked brain changes through repeated scans in children and adolescents. They analyzed the gray matterwhich can be considered the “thinking” component of the brain.
Researchers discovered that, during adolescence, gray matter goes through a process called “pruning”. That is, in the early stages of life, the brain establishes an enormous number of neuronal connections; But as we age, it gradually cuts back on those that are used less frequently and strengthens those that remain.
The growth and subsequent volume loss of gray matter is essential for brain development.
The brain matures in phases
In one investigation Led by neuroscientist Nitin Gogtay, the brains of a series of children as young as four were scanned, beginning to track their evolution every two years. This is how scientists discovered that, within the frontal lobe, regions mature from back to front.
More primitive regions, such as areas responsible for voluntary muscle movement, develop first, while more advanced regions, important for decision-making, emotional regulation, and social behavior, had not fully matured by the time they turned 20 and tracking ended.
Because data collection stopped after 20 years, the researchers could not determine precisely when development ended. The age of 25 became the best estimate of the assumed end point.
What the latest research reveals
Since those first studies, neuroscience has advanced considerably. Instead of examining individual regions in isolation, researchers now study how efficiently different parts of the brain communicate with each other.
A important recent study evaluated the efficiency of brain networks, essentially how the brain is connected, through the topology of the white matter. White matter is made up of long nerve fibers that connect different parts of the brain and spinal cord, allowing electrical signals to travel in both directions.
Researchers analyzed scans of more than 4,200 people, from infancy to age 90, and found several key periods of developmentincluding one between the ages of 9 and 32, which they called “adolescence.”
For anyone who has reached adulthood, it may come as a shock to be told that your brain is still “adolescent” at 30. But this term only implies that your brain is in a stage of key changes.
According to this study, it appears that during cerebral adolescence, the brain balances two key processes: segregation and integration. Segregation consists of building “neighborhoods” of related thoughts. Integration is equivalent to building “highways” to connect these neighborhoods. Research suggests that this construction does not stabilize into a pattern that we can consider “adult” until we are thirty.
The study also found that “small scale” – a measure of network efficiency – was the strongest predictor of identifying brain age in this group. If we compare it to a public transportation system, and imagine routes that require stops and transfers, increasing the “small scale” is like adding express lanes. Basically, more complex thoughts have more efficient routes through the brain.
However, this brain infrastructure does not last forever. After age 32, there is a turning point at which these developmental trends change direction. The brain stops giving priority to the “highways” and returns to segregation to establish the routes it uses the most.
In other words, during adolescence and 20 years, the brain connects, and by age 30, it dedicates itself to settling and maintaining the most used routes.
Making the most of a brain under construction
If our brains are still under construction throughout our twenties, how do we ensure we’re building the best structure possible? One answer lies in enhancing the neuroplasticitythe brain’s ability to reconfigure itself.
Although the brain continues to change throughout life, the period between 9 and 32 years of age represents a unique opportunity for structural growth. Research suggests that there are many ways to promote neuroplasticity.
He high intensity aerobic exercise, learn new languages and practice hobbies that require great cognitive effort, such as chess, can strengthen the neuroplastic capabilities of your brain, while chronic stress can hinder them.
For those aiming to have a high-performing brain by age 30, it’s helpful to challenge it in your 20s, although it’s never too late to start.
Taylor SnowdenPost-Doctoral Fellow, Neuroscience, University of Montreal
This article was published in The Conversation. Read the original.
