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Popular wisdom holds we can ‘rewire’ our brains: after a stroke, after trauma, after learning a new skill, even with 10 minutes a day on the right app. The phrase is everywhere, offering something most of us want to believe: that when the brain suffers an assault, it can be restored with mechanical precision. But ‘rewiring’ is a risky metaphor. It borrows its confidence from engineering, where a faulty system can be repaired by swapping out the right component; it also smuggles that confidence into biology, where change is slower, messier and often incomplete. The phrase has become a cultural mantra that is easier to comprehend than the scientific term, neuroplasticity – the brain’s ability to change and form new neural connections throughout life.

But what does it really mean to ‘rewire’ the brain? Is it a helpful shorthand for describing the remarkable plasticity of our nervous system or has it become a misleading oversimplification that distorts our grasp of science?

After all, ‘rewiring your brain’ sounds like more than metaphor. It implies an engineering project: a system whose parts can be removed, replaced and optimised. The promise is both alluring and oddly mechanical. The metaphor actually did come from engineering. To an engineer, rewiring means replacing old and faulty circuits with new ones. As the vocabulary of technology crept into everyday life, it brought with it a new way of thinking about the human mind.

Medical roots of the phrase trace back to 1912, when the British surgeon W Deane Butcher compared the body’s neural system to a house’s electrical wiring, describing how nerves connect to muscles much like wires connect appliances to a power source. By the 1920s, the Harvard psychologist Leonard Troland was referring to the visual system as ‘an extremely intricate telegraphic system’, reinforcing the comparison between brain function and electrical networks.

The metaphor of rewiring also draws strength from changing theories in developmental neuroscience. The brain was thought to be largely static after childhood, becoming a fixed network of circuits, much like a hardwired radio. But beginning in the 1960s, researchers showed that the brain was far more adaptable. Stroke patients could regain function by recruiting new areas of the brain.

These findings revolutionised rehabilitation medicine. They also gave rise to an idea that would quickly leap beyond the clinic: if brains can rewire, then people can change.

More recently, the metaphor of neural rewiring has gained popularity alongside new imaging techniques like fMRI and PET scans, which allow researchers to see brain activity in ways never before possible. In studies of stroke recovery, clinicians often observe increased activation in brain regions adjacent to or distant from the area of damage. This is interpreted as the brain ‘rewiring’ itself to restore lost function. Popular science writers have embraced the metaphor as well, using it to explain everything from trauma healing to learning a second language.

But unlike electrical wiring, which follows rigid, fixed paths, the brain’s connectivity is dynamic and constantly changing. Neurons form and prune synapses – the connections between them – in response to activity and environment, a process governed by complex biochemical signalling rather than simple rerouting. Even when we can map the parts, the picture doesn’t explain the self. As late as 2013, Francis Collins, the then-director of the US National Institutes of Health (NIH), complained about studies on mapping the brain, in an interview with NPR (US National Public Radio): ‘It’d be like, you know, taking your laptop and prying the top off and staring at the parts inside, you’d be able to say, yeah, this is connected to that, but you wouldn’t know how it worked.’

To evaluate the metaphor, it’s important to grasp how brain plasticity actually works. We already know a lot about the brain’s remarkable ability to reorganise itself throughout life by forming new neural connections, strengthening existing ones or rerouting functions to undamaged areas. But the logic of neuroplasticity isn’t the same as swapping one wire with another. It’s more like a living forest where paths are gradually worn or abandoned based on use. It involves changes at the cellular level and can occur in response to learning, memory, sensory input and trauma. Importantly, while neuroplasticity is a lifelong feature of the brain, it is more robust during youth and becomes more effort-dependent with age.

This capacity allows the brain to adapt to new experiences, recover from injuries, learn new information and compensate for lost functions. Neuroplasticity is real, but it’s not magic. It has limits. It requires effort. And it doesn’t always result in perfect recovery or transformation.

Unlike rewiring a machine, plasticity is not as simple as replacing parts. It’s a gradual process and is often inefficient. Synapses, which pass signals between neurons, strengthen or weaken. New dendritic branches – neurons’ treelike extensions – grow while others retract. Entire networks shift their activity over time, but only under the right conditions, and these changes accumulate to support new patterns of function while overall mechanisms become less efficient across the lifespan.

Plasticity is conditional, uneven and shaped by circumstance, not wishful thinking

Plasticity happens throughout life, but it’s shaped by many factors: age, environment, repetition, rest, nutrition and emotional state. For example: with months of targeted physical therapy, a stroke survivor can regain movement in a limb by recruiting healthier networks; with intensive, structured practice, a child with dyslexia can gradually develop new reading pathways; and reading braille requires extensive practice and is instrumental in changing relevant brain regions.

In cases of childhood trauma, certain survival pathways, such as hypervigilance or emotional detachment, may become dominant and reinforced over time. Later in life, therapy may promote the strengthening of alternative circuits related to trust, emotional regulation or self-awareness. But the old pathways aren’t necessarily erased. They remain in the background, potentially reactivated under stress. The idea that the brain........

© Aeon