Neuroplasticity: how your brain rewires itself

Your brain isn’t fixed after childhood. It keeps changing its connections, and even its structure, in response to what you do. Here’s what the evidence actually shows.

By the Daily Recall team · Updated October 3, 2026 · 10 sources

Neuroplasticity is the nervous system’s ability to change its activity, structure and connections in response to experience. For much of the 20th century, scientists assumed the adult brain was largely fixed. We now know it keeps reorganizing throughout life, and you can see that happening on brain scans.

Neurons that fire together, wire together

In 1949 the psychologist Donald Hebb proposed that when two neurons are repeatedly active at the same time, the connection between them gets stronger. That idea, often shortened to “neurons that fire together, wire together”, is still the core of how scientists think about learning. Practising a skill, revisiting a memory or repeating a habit strengthens the pathways involved. Neglected pathways weaken.

Plasticity happens at several levels: individual synapses get stronger or weaker within minutes, new connections sprout over days and weeks, and with long practice whole regions can change in size.

The studies that changed the picture

London taxi drivers. To get a licence, London cabbies memorize the city’s tangle of streets, a test known as “the Knowledge”. In 2000, Eleanor Maguire’s team scanned 16 licensed drivers and found the back part of their hippocampus, a region key to spatial memory, was larger than in 50 non-drivers, and the more years they’d driven, the larger it was. A follow-up of 79 trainees showed this was cause, not coincidence: only the 39 who qualified gained grey matter there. Interestingly, the qualified drivers did worse on some other visual memory tasks, a hint that the brain may trade some abilities for others.

Juggling. In 2004, Bogdan Draganski’s team scanned people before and after 3 months of learning to juggle. Grey matter grew in areas that track visual motion, then partly shrank back once they stopped practising. Plasticity works both ways: use it or lose it.

Stroke rehabilitation. In the EXCITE trial, 222 stroke patients had their good arm restrained so they were forced to use the weaker one for hours of training each weekday over 2 weeks. Their arm function improved more than with usual care, and the gains lasted at least a year. The brain had rerouted control around the damage.

Can adults grow new neurons?

This is one of neuroscience’s live debates. In 2018, a Nature study by Sorrells and colleagues examined brain tissue from adults aged 18 to 77 and found almost no young neurons, concluding that new neuron production drops sharply in the first year of life. A month later, a study in Cell Stem Cell by Boldrini and colleagues examined 28 people aged 14 to 79 and found older adults produced similar numbers of new neurons to younger ones.

Why the disagreement? A review by Kempermann and others points to methods: the protein used to spot young neurons breaks down after death, and the time before tissue was preserved varied from hours to days. The honest answer is that adult neurogenesis in humans is probably real but small, limited to part of the hippocampus, and still unsettled. Plasticity doesn’t depend on it, though: most of the brain’s change comes from rewiring existing neurons.

What actually supports plasticity

• Learning something genuinely new. The taxi and juggling studies both involved demanding new skills, practised for months. Novelty and challenge matter more than repetition of what you already know.
• Practice, spaced over time. Repetition is what strengthens a pathway. Spreading it out helps it stick; see spaced repetition.
• Aerobic exercise. In a 2011 trial, a year of walking 3 times a week increased hippocampal volume by about 2% in older adults, while a stretching group’s volume shrank. Exercise raises BDNF, a protein that supports the growth and survival of neurons. More in exercise and memory.
• Sleep. The brain consolidates new learning during sleep. See sleep and memory.
• Motivation. Reward and attention signals, including dopamine, help decide which experiences get stored.

Myths about neuroplasticity

“Brain games will rewire your brain and prevent dementia.” Practising a game makes you better at that game; broad benefits to everyday life are much harder to show. In 2016 the US Federal Trade Commission fined Lumosity $2 million for unsupported claims, including about delaying cognitive decline. Our guide do brain games work? covers the evidence.

“You can rewire your brain in 21 days.” Change is real but gradual, and it depends on what you practise, how often and for how long.

“Once a change is made, it’s permanent.” The juggling gains partly reversed when practice stopped.

Give your brain something new

Novel challenges are the raw material of plasticity. Matching colors from memory is one most people have never practised, which is exactly why it’s a good one. Try it:

The full daily version is Hue: study a scene for 8 seconds, then rebuild its colors from memory. It’s a fun daily challenge rather than a treatment, but it’s a genuinely new skill to get better at.

Sources

1. StatPearls (NCBI): Neuroplasticity
2. Maguire et al. (2000), PNAS: navigation-related structural change in the hippocampi of taxi drivers
3. Woollett & Maguire (2011), Current Biology: taxi trainees followed over time (ScienceDaily summary)
4. Draganski et al. (2004), Nature: changes in grey matter induced by training
5. Wolf et al. (2006), JAMA: EXCITE stroke rehabilitation trial (NICHD)
6. Sorrells et al. (2018), Nature: neurogenesis drops sharply in children
7. Boldrini et al. (2018), Cell Stem Cell: neurogenesis persists in older adults (EurekAlert)
8. Kempermann et al. (2018), Cell Stem Cell: human adult neurogenesis, evidence and remaining questions
9. Erickson et al. (2011), PNAS: exercise training increases size of hippocampus
10. FTC (2016): Lumosity to pay $2 million to settle deceptive advertising charges

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