8/4/2026
Yesterday I wrote that the prefrontal cortex is one of the last major brain regions to mature, with its structural and functional development continuing through adolescence and into the third decade of life.
But development doesn't stop there. The brain remains plastic throughout life. Learning, experience, and our environment can continue to reshape neural connections and brain function.
That means how we live matters.
Healthy habits such as adequate sleep, regular aerobic exercise, mindfulness, and sustained mental engagement can support cognitive and prefrontal function.
Chronic stress, sleep deprivation, and prolonged social isolation, on the other hand, are associated with changes in brain structure and function, including in regions involved in decision-making, social cognition, and emotional regulation.
Studies indicate prolonged social isolation reduces grey matter density within the prefrontal cortex. Loneliness may feel like an emotion, but research suggests that chronic loneliness is associated with measurable changes in the brain, including areas involved in decision-making, social cognition, and emotional regulation.
Another factor deserves special attention: our information diet.
Informational junk food: Short-form videos, constant notifications, and algorithmically curated feeds are designed to capture attention and encourage rapid, repeated engagement. They require little sustained concentration and can train us toward constant stimulation and instant gratification.
Just as our physical bodies are shaped by what we repeatedly consume, our minds are shaped by what we repeatedly pay attention to. If we spend hours jumping from one short video to another, our ability to sit quietly with a book, think through a difficult problem, or sustain a conversation may suffer.
That doesn't mean dopamine “pleasure chemical” simply “overpower” our PFC.
Dopamine plays an important role in motivation, learning, and reward prediction. It can increase the anticipation and pursuit of a rewarding experience. That's one reason an endless stream of potentially interesting videos can keep us scrolling: believing the next one might be better.
Over time, repeated behaviors can also become habits. Brain circuits involving the striatum and other regions help automate familiar behaviors, reducing the need for conscious deliberation each time we perform them.
That's why mindlessly opening a short-video app can feel almost automatic. We don't necessarily make a fresh decision every time. The habit has made the decision easier.
So perhaps the answer is to design our environment and habits so that our better judgment gets a chance to operate.
Get enough sleep.
Exercise regularly.
Spend time with real people.
Read something longer than a few minutes.
Work on one thing without constantly switching.
And protect some part of each day from algorithmic feeds and notifications.
Even thirty minutes of uninterrupted reading, writing, thinking, or face-to-face conversation can be a small act of resistance against constant stimulation.
We spend a great deal of effort taking care of our bodies. We should be equally taking care of the part of our brain that helps us pause, think, choose, and decide what kind of person we want to become.
