A BIZARRE illusion that makes people believe a false hand is part of their own body could be all it takes to imbue prosthetic limbs with a sense of touch.
Although sophisticated robotic prosthetics can now replace amputated hands, they don't yet provide the brain with the sensory feedback vital to control fine movement. Without feeling pressure from the fingertips, for example, an amputee operating a robotic hand could either break a wine glass by grasping it too tightly, or let it fall to the floor by failing to apply enough grip.
One potential solution is to wire sensors in robotic fingers directly into nerves in the stump, but this poses some technical challenges. So instead Henrik Ehrsson, a cognitive neuroscientist at the Karolinska Institute in Stockholm, Sweden, decided to see if a trick known as the "rubber hand illusion" could provide a simpler alternative.
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