The mind re-maps the body: learning to live with your cybernetic centaur legs

Paul Raven @ 24-06-2009

Good news for wannabe cyborgs and transhumans! New Scientist reports on another manifestation of plasticity in the human mind; it turns out that tool use results in a remapping of the mind’s perception of the body, which in turn suggests that adapting to artificial prosthetics or cyborg bolt-ons is within the capability of our baseline brains.

The brain maintains a physical map of the body, with different areas in charge of different body parts. Researchers have suggested that when we use tools, our brains incorporate them into this map.

To test the idea, Alessandro Farné of the University of Claude Bernard in Lyon, France, and colleagues attached a mechanical grabber to the arms of 14 volunteers. The modified subjects then used the grabber to pick up out-of-reach objects.

Shortly afterwards, the volunteers perceived touches on their elbow and fingertip as further apart than they really were, and took longer to point to or grasp objects with their hand than prior to using the tool.

The explanation, say the team, is that their brains had adjusted the brain areas that normally control the arm to account for the tool and not yet adjusted back to normal.

“This is the first evidence that tool use alters the body [map],” says Farné.

Farné says the same kind of brain “plasticity” might be involved in regaining control of a transplanted hand or a prosthetic limb when the original has been lost. The brain might also readily incorporate cyborg additions – a cyborg arm or other body part – into its body schema, says Farné, “and possibly new body parts differing in shape and/or number, for example four arms.”

So, good news should you decide that you want to become a permanent cyber-centaur by wearing these things: