Brain development: 10 ways your brain changes as you get older

One of the many amazing facts about your brain is that your grey matter is always changing, even through adulthood. In addition to the certain things that can rewire your brain – like your diet and trying new things – it never stops changing. Here’s a look at the brain development you go through at every age, according to experts.

Check out these morning brain exercises to clear your mind.

Before you took your first breath, your body was busy with brain development, preparing for life outside the womb. Newborns have about 100 billion neurons, says neurologist, Dr David Perlmutter. “That means the average rate of growth of brain cells during pregnancy is about 250,000 new brain cells per minute,” he says.

Read on for the baby care advice you used to get from grandparents.

At birth, your brain is about 60 per cent of the size it will be when you’re full-grown, says professor of neurology, Dr Frances Jensen. Your brain starts at about 350 grams, then grows another 230 grams in the first 90 days after birth, says Dr. Perlmutter. “It comes close to doubling within the first three months,” he says.

By the time you’re three years old, your brain is about 80 per cent of its adult size in terms of volume and brain cells, says Dr Perlmutter. “The brain of a 3-year-old is extremely sophisticated and might be more [sophisticated] than any other animal on the planet,” he says. At that age, the brain actually has 200 per cent more synapses than an adult’s. As brain development continues, your mind starts “pruning” by breaking down those synapses. Getting rid of the connections it doesn’t use lets the brain focus its energy on the connections that matter.

Find out why Japanese children are the healthiest in the world.

The years leading up to a child’s fifth birthday are part of the “critical period” of development, says Dr Jensen. At this point, experiences are directly shaping the way synapses form. “Everyone’s brain is being customised for their environment,” says Dr Jensen. On one hand, this means negative experiences can leave a psychological scar on the child forever. But on the flip side, it also means early intervention programmes and efforts to reverse the effects of traumatic experiences are more effective than ever.

Check out these childhood hobbies that double as incredible kilojoule-burning workouts.

Teen brains look adult-like in terms of weight, but they aren’t fully developed yet. Your body has been producing myelin from the back of the brain (which is in charge of the most basic functions) to the front (which has more complex circuits). The last area to be fully myelinated is the frontal lobe, which is important for decision-making, impulse control and empathy, says Dr Jensen. While an adult’s frontal lobe knows when to say “no” to peer pressure and risks, adolescents haven’t developed that skill yet. “It’s like a Ferrari with weak brakes,” says Dr Jensen. Mum and Dad may be tearing their hair out at a teen’s bad decisions, she explains, but parents should practise patience and provide guidance: teens need “frontal lobe assists” to avoid poor choices.

Read on for tips on how to have a happy teenager.

By the time you’re in your mid to late 20s, the brain development of your frontal lobe has finally finished myelination – especially in the frontal lobes you need for judgment. You’ll continue forming and eliminating synapses and brain cells your whole life, but there is one potential drawback to the development of your frontal lobe: now, mental illnesses like schizophrenia or anxiety can flare up. About 60 to 80 per cent of people with major affective disorders are diagnosed between 18 and 25, says Dr Jensen. “The frontal lobe needs to be connected up to a point to be able to manifest these diseases,” she says.

Check out these silent signs of high-functioning anxiety.

In your 20s, your brain slows down the production of brain cells and synapses – plus it’s not doing as much “pruning” – which is why you have a harder time learning by the time you reach your 30s. Meanwhile, your diet and exercise habits are setting you up for a strong – or forgetful – mind in the decades ahead.

Find out which foods are worst for your brain here.

Most people start noticing their mind slipping in their 50s, starting with short-term memory. “We call these ‘senior moments’ and write it off and make jokes,” says Dr Perlmutter. Still, about 5 per cent of Alzheimer’s diagnoses are early-onset, so don’t ignore symptoms that could be a sign of serious memory loss.

Don’t miss these things to start doing at 50 that’ll save your brain at 80.

One in 10 adults age 65 and up have Alzheimer’s disease. Between genetics and lifestyle risks, the risk doubles every five years after age 65. The causes of the condition aren’t entirely clear, but scientists do know as we age, our brain cells and synapses decline. “These connections are dropping away, so the signals don’t get from here to there,” says Dr Perlmutter. “You look at an object and suddenly can’t name it anymore because you can’t connect to the part of the brain where the name was stored.”

Don’t miss these signs of early-onset Alzheimer’s disease.