People born with only one hand compensate with new neural pathways that re-organize parts of their brain, new research shows, possibly shaking up our fundamental understanding of how the brain operates.

Why it matters: Our brain could be organizing itself around the function of what it wants to accomplish — not the body part. "It's kind of mind blowing for me to think we could have been getting this wrong for so long," said Tamar Makin, a neuroscientist at University College London. "The implications, if this interpretation is correct, are massive."

The details: In the study, published in Current Biology, researchers looked at regions of the brain that would normally "light up" with the missing hand's activity. Instead, they found that the brain's activity was lighting up from the activity of other body parts (like the arm, foot and mouth) that were compensating for the missing hand. The participants' brains were scanned with functional MRI as they performed tasks.

What's next: This new study shows remarkable brain plasticity, which could lead to new research on how to encourage the brain to control artificial limbs or body parts.