Your changing brain: neuroplasticity

Brain cells talk to each other through tiny connections. The brain is always forming new connections, reshaping branches and replacing old links, in response to what we do and feel.

Scientists call this “use it or lose it.” When a skill is not used for a long time, the brain areas behind it can lose some of their strength.

In young children, the brain trims connections it doesn’t use (called pruning). This makes the remaining circuits work better.

Brain scans show that practice and experience can change the amount of grey matter in certain areas. They can also change how brain areas work together.

Age, sex, health, brain injury or illness, and even personality traits can all affect how easily a person’s brain changes.

London taxi drivers must learn thousands of streets. Brain scans showed that the back part of their hippocampus, which helps with mental maps, was larger than in people who didn’t drive taxis.

The longer someone had been a taxi driver, the larger this area tended to be. The researchers concluded that the healthy adult brain can change its structure to meet everyday demands.

Young adults who learned to juggle three balls showed growth in brain areas that process movement and vision. People who didn’t learn showed no change.

Three months after they stopped juggling, some of that growth faded again, though not all of it. The brain kept what it was using.

Some principles of brain change

• Intensity matters: practice needs to be challenging enough
• Repetition matters: change needs plenty of practice
• Specificity: the brain gets better at exactly what you practice
• Use it and improve it: training a skill can strengthen it
• Use it or lose it: skills you stop using can weaken

More than a million new brain connections form every second in the first few years. Then the brain trims the ones it doesn’t use, making its circuits more efficient.

Back-and-forth moments with caring adults, like a baby babbling and a parent answering, are called “serve and return.” These moments are essential for healthy brain building.

The teen brain is still developing. The front of the brain, which helps with planning, prioritizing and decisions, is one of the last areas to mature.

The teen years are also a time of great opportunity. The growing brain is ready to learn and adapt.

Studies of taxi drivers and adult learners show the adult brain can still change its structure in response to what it is asked to do.

Some brain changes come with age. But the older brain can increase its activity and build new support networks to keep thinking working well.

In one trial, a year of walking-based exercise grew the hippocampus in older adults by about 2%, roughly reversing one to two years of age-related shrinking.

The time it took ranged from 18 days to an estimated 254 days. Exercise habits took about one and a half times as long as eating or drinking habits.

Missing one day had little effect on building the habit. Missing many days did make it harder for the habit to become fully automatic.

People in the habit study tied their new habit to a daily cue, like “after morning coffee” or “with lunch.” Doing it in the same situation each day helps it become automatic.

Examples

• After brushing my teeth, I’ll do two minutes of slow breathing
• After dinner, I’ll walk around the block
• When I sit on the bus, I’ll practice five words in a new language

Because the brain keeps changing with practice, new patterns can be learned even after years of old ones. Specific practice of the new pattern is what makes the change.

Recovery after brain injury uses the same brain changes that help us learn. The brain rewires and strengthens connections in the networks that survived.

Research suggests a time-limited window of extra brain flexibility opens after a stroke. This is when the biggest gains in recovery usually happen.

Rehab programs are tailored to practice the skills affected by the stroke, such as walking, grip, coordination, or speaking and understanding.

Rehab also teaches new ways to work around changes that stay, like dressing with one hand or using tools to communicate.

How much someone recovers depends on things like how severe the damage was and their age. Children and young adults often recover more than older adults.

Medical students under a month of heavy exam stress had more trouble shifting attention, and brain scans showed changes in attention networks. One month after the stress eased, they looked the same as students who weren’t stressed.

In a small study, stressed adults took an 8-week mindfulness course. The more their stress went down, the more the grey matter in part of the amygdala (the brain’s alarm center) decreased.

Difficult early experiences can have lasting effects on brain and body. Researchers also stress that the brain’s ability to change gives real hope for healing.

Supportive relationships with caring adults can help buffer a child’s stress response.

During deep sleep, the brain replays new memories and moves them into long-term storage. Sleep after learning helps it stick.

In older adults, a year of walking-based exercise increased the size of the hippocampus. This was linked to higher levels of a protein that helps brain cells grow.

Training effects can last a long time, but skills practiced in one area don’t always spread to others. Staying engaged in a life that takes ongoing mental effort may support thinking more broadly.

The brain changes most with practice that is specific, repeated and challenging enough. Choosing something you care about makes it easier to keep going.

Brain flexibility is greatest early on, but adults and older adults can still change their brains through learning and experience.

Training can improve the skill being trained, and those gains can last. But there is limited evidence that the benefits spread to other kinds of thinking.

Brain change needs enough repetition and enough intensity. New habits took an average of 66 days to feel automatic.

After a stroke, healthy brain areas can take over some jobs of the damaged area, and practice helps drive this. Recovery varies a lot from person to person.

In one study, changes from a month of heavy stress were gone a month after the stress eased. The brain’s flexibility gives hope for healing.

Simple ways to “serve and return”

• Answer your baby’s sounds and faces
• Name what your child is looking at or doing
• Play simple turn-taking games
• Put the phone down during talk and play
• Read and talk together every day

Ways to help

• Ask the rehab team what to practice at home
• Celebrate small wins
• Give extra time instead of doing things for them
• Join in practice when you can
• Notice their mood, and encourage support if they feel low

New habits take time and missed days are normal. Encouraging someone to keep going, rather than judging slips, helps them stick with it.