The human brain carries a highly detailed map of the body, with different regions linked to specific parts—arms, lips, legs, and beyond. But what happens to this map when a limb is lost?
For years, neuroscientists believed that after amputation, the brain quickly rewired itself, allowing nearby body parts to take over the space once devoted to the missing limb. This supposed large-scale remapping became a cornerstone of what scientists call adult brain plasticity—the brain’s ability to adapt its structure and functions in response to injury, experience, or learning.
A recent study published in Nature Neuroscience challenges this long-standing view. The findings show that the brain’s body map remains surprisingly stable, even years after a limb has been removed.
To investigate, researchers worked with National Health Service (NHS) surgeons and followed three adult patients undergoing arm amputations due to conditions like cancer or severe circulatory issues. Using functional MRI scans both before surgery and for up to five years afterward, they tracked how the brain responded when patients moved different body parts—fingers, toes, lips—and later, when they attempted to move their missing (phantom) fingers.
Remarkably, the brain’s map of the hand remained intact in all three cases. It did not merge with neighboring areas such as the face. This stability may explain why amputees continue to sense their missing limbs so vividly.
However, phantom sensations are often painful—described as burning, stabbing, or itching. For decades, scientists blamed brain reorganization for these sensations, inspiring treatments like mirror therapy, VR training, and sensory retraining. But these therapies have rarely been more effective than placebos. The new results suggest why: if the brain’s map is unchanged, trying to “fix” it is pointless.
Instead, the root cause may lie in damaged peripheral nerves, which can form tangled bundles and misfire signals to the brain. This has spurred the development of new surgical techniques designed to preserve nerve connections and prevent faulty signaling.
The study also carries important implications for prosthetics and brain-computer interfaces. Because the brain’s original map is preserved, advanced devices could tap into it—either decoding intended movements or stimulating it electrically so that amputees can “feel” through their prosthetic limb.
Ultimately, the research shows that our brains maintain a strong and enduring model of the body, even without sensory input. For amputees, this means the lost limb continues to exist in the brain’s representation—sometimes as a source of pain, but also as a powerful gateway to future technologies.
