Science

Brain Electrodes Make Winter Soldier's Fake Arm Feel Like His Own

Marvel’s Winter Soldier, newly landed at Netflix, owes his abilities to the scientists that installed his prosthetic arm. No matter how much power Bucky Barnes’ Communist-starred cybernetic limb would have yielded on its own, it wouldn’t have been very useful to him if it wasn’t hooked up properly his brain, allowing him to feel like it was really his. Scientists, attempting to catch up to Marvel’s science, have just managed to induce this feeling in amputees IRL.

In an article recently published in the journal PNAS, a team of neuroscientists report that they’ve successfully convinced two people with artificial limbs that their prostheses actually belong to them. While we take it for granted that the arms of fictional prosthetic-limbed characters like Barnes and Darth Vader are integrated seamlessly into their minds and bodies, accomplishing this in real life is actually incredibly difficult.

“Creating a prosthetic device that feels like one’s own limb is a major challenge in applied neuroscience,” the authors wrote in their paper.

The team convinced its subjects that their prostheses were actual extensions of their bodies and not just pieces of plastic attached to their flesh by using electrical brain stimulation, a process by which certain regions of the brain are activated with electrical currents. In particular, the researchers stimulated a part of the brain known as the hand somatosensory cortex — the region that processes perception of the hand’s internal or surface state — while they simultaneously touched the artificial limb’s hand in full sight of the subject. The combination of seeing the hand being touched and receiving electrical stimulation to the right part of the brain proved to be enough to convince that the owner of the prosthetic limb that it actually belonged to them.

Their successful results, the researchers write, open up a wealth of new options for the brain, showing that it’s capable of adding together “natural” visual input and artificial brain stimulation to equal a sensation akin to ownership. While other scientists working on artificial limbs have succeeded in creating prostheses that can generate the sense of touch in the brain or be controlled using the brain, this new discovery solves the more existential issue that concerns owners of artificial limbs: Is this arm actually mine? If this research continues to develop successfully, soon they won’t even have to ask.

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