Neuroplasticity Explained: How to Rewire Your Brain and Keep It Sharp at Any Age

For a long time, scientists believed the adult brain was more or less fixed. You got what you got by early adulthood, and after that it was a slow, steady decline. Old dogs, new tricks, and all that.

That turned out to be wrong, and it's one of the most hopeful discoveries in modern science. Your brain keeps changing, all your life, in response to what you do with it. Every skill you practice, every language you learn, every habit you build literally reshapes your brain's wiring.

Here's what neuroplasticity really means, the fascinating research behind it, what it can and can't do, and the everyday habits that help keep your brain healthy and sharp at any age.

What is neuroplasticity?

Neuroplasticity, also called brain plasticity, is the brain's ability to change its structure and function in response to experience, learning or injury.

Your brain contains about 86 billion neurons, each connected to many others through junctions called synapses. When you learn something, connections between brain cells that fire together get stronger. Connections you don't use can weaken and be pruned away. Neuroscientists often sum this up with a phrase based on the work of psychologist Donald Hebb: "neurons that fire together, wire together."

Practice literally shapes the wiring. It's why you can learn to drive, pick up an instrument at 50, master a new job or recover some function after a stroke with rehab.

Types of neuroplasticity

• Structural plasticity: physical changes in the brain, such as new connections between neurons or changes in the size of brain regions
• Functional plasticity: the brain's ability to shift functions from damaged areas to healthy ones, which is key to recovery after injury
• Synaptic plasticity: connections between neurons getting stronger or weaker with use

The London taxi driver study

London's black-cab drivers have to memorize a huge map of the city's 25,000 or so streets and thousands of landmarks, known as "the Knowledge." It typically takes years of study.

In 2000, researchers led by Eleanor Maguire at University College London scanned the brains of licensed taxi drivers. They found the drivers had a larger rear part of the hippocampus, a region important for spatial memory and navigation, than people who weren't taxi drivers. The longer someone had been driving a cab, the larger it tended to be.

Later work by the same group followed trainees over several years and found hippocampal changes in those who qualified, but not in those who failed or in non-trainees. That suggests the learning itself played a part.

The juggling study

In a 2004 study published in Nature, adults who had never juggled spent three months learning a three-ball routine. Brain scans showed increases in gray matter in areas involved in processing visual motion. When they stopped practicing for three months, those areas shrank back somewhat.

Later research found similar changes in older adults learning to juggle, though they were smaller. The lesson: the adult brain responds to new skills, at any age, and it responds to use. "Use it or lose it" has real truth to it.

Can adults grow new brain cells?

For decades, scientists believed we stopped making new neurons after childhood. Then studies found evidence of neurogenesis, the birth of new neurons, in the adult hippocampus in some animals and people.

Whether adult humans make many new neurons is still hotly debated. In 2018, two major studies reached opposite conclusions. What's not debated is that the adult brain constantly forms and strengthens connections between existing neurons, which is the main way we learn.

Neuroplasticity in childhood vs. adulthood

Children's brains are especially plastic. In the first years of life, the brain forms connections at an astonishing pace, then prunes away the ones that aren't used. That's why early experiences, like being talked to, read to and played with, matter so much, and why young children can pick up languages and accents so easily.

There are also "sensitive periods" when certain skills develop most easily. For example, children born with cataracts need treatment early for normal vision to develop, because the visual system wires itself in the first years of life.

Adult brains are less dramatically plastic, but they remain adaptable throughout life. Adults tend to learn best with focused attention, clear goals, repetition and feedback, which is good news, because those are things you can control. Learning in adulthood may take a bit more effort, but it absolutely happens.

Neuroplasticity after stroke and brain injury

One of the most powerful real-world examples of neuroplasticity is recovery after a stroke or brain injury. Healthy parts of the brain can take over some functions of damaged areas, especially with intensive, repetitive rehabilitation. Techniques like constraint-induced movement therapy, where the stronger arm is restrained so the person must use the weaker one, rely on this principle. Recovery is often greatest in the first months, but improvement can continue for years with practice.

Neuroplasticity and habits

Plasticity works both ways. Habits you repeat, including unhelpful ones like constant phone checking or anxious thought patterns, get reinforced too. The upside is that new, healthier habits can be built through repetition. Therapies like cognitive behavioral therapy (CBT) work partly by repeatedly practicing new ways of thinking and responding.

What neuroplasticity doesn't mean

The word gets stretched a lot, especially in marketing. A few reality checks:

• Brain-training games aren't magic. In 2014, a group of about 70 scientists organized by the Stanford Center on Longevity signed a statement saying there was little evidence that brain games improve everyday thinking. You mostly get better at the game itself. In 2016, the Federal Trade Commission fined the makers of one popular brain-training app for unsupported claims.
• You can't "rewire" your brain overnight. Real changes come from lots of practice over weeks and months.
• It's not unlimited. Some abilities are harder to change than others, and plasticity tends to be greater in childhood.
• "Neuroplasticity" supplements generally lack good evidence.

What genuinely helps your brain stay sharp

The evidence is strongest for things that are good for your whole body and life.

Learn genuinely new, challenging things

A language, an instrument, a craft, a dance style, a new job skill. In the Synapse Project, published in 2014, older adults who spent about 15 hours a week for three months learning demanding new skills like digital photography or quilting showed improved memory compared with people doing easier, familiar activities. See learning a language as an adult.

Move your body

Exercise is one of the best things you can do for your brain. It boosts blood flow and a protein called BDNF (brain-derived neurotrophic factor), which supports the growth and survival of brain cells. Aerobic exercise has been linked with a larger hippocampus in older adults. (150 minutes a week is the guideline.)

Sleep well

Your brain consolidates new learning while you sleep and clears out waste products. See how much sleep adults need.

Stay socially connected

Conversation and relationships are mentally demanding in a good way. Loneliness and isolation are linked with a higher risk of dementia. See loneliness and health.

Protect your heart and hearing

What's good for your heart is good for your brain. Managing blood pressure, blood sugar and cholesterol matters. Hearing loss is also one of the biggest modifiable risk factors for dementia identified by the Lancet Commission on dementia, so getting hearing checked and using hearing aids if needed is important.

Manage stress

Chronic stress and high cortisol can affect the hippocampus. Practices like mindfulness may help. See what is stress?

Eat a brain-friendly diet

The Mediterranean and MIND diets, rich in vegetables, berries, beans, whole grains, fish, nuts and olive oil, are linked with better brain health in observational studies.

Limit alcohol and don't smoke

Both are linked with brain shrinkage and higher dementia risk.

Keep it challenging: the sweet spot for learning

The key is novelty and effort. If something feels easy and automatic, you're not stretching much. If it feels slightly too hard and a little frustrating, you're in the zone where learning happens. Psychologists call this "desirable difficulty." Our guide to how to remember what you learn explains how to use it.

Frequently asked questions about neuroplasticity

Is neuroplasticity real?

Yes. It's one of the best-established findings in neuroscience, though popular claims about it are often exaggerated.

How long does it take to rewire your brain?

It depends on the skill, but meaningful changes usually take weeks to months of regular practice.

Can meditation change your brain?

Some studies have found differences in brain structure and activity in people who meditate regularly, though findings vary and many studies are small. Meditation's benefits for stress are better established.

Do crossword puzzles prevent dementia?

People who do puzzles tend to have sharper thinking, but it's not clear that puzzles prevent dementia. Learning new, varied skills plus exercise and social connection is a better bet.

Give your brain something new to chew on. Our free wellness wheel quiz is a good place to start.