One of the most amazing things about the current state of medical science is how quickly we seem to be learning to replace, rebuild, and transplant parts of our bodies that we thought we’d lost for good. For people who have lost flesh and limb and the sensations that go with them, recent research into neuroprosthetics has offered the hope of a restored sense of touch. One especially groundbreaking paper from earlier this month illustrates how promising this area of research is:
We show that implanted peripheral nerve interfaces in two human subjects with upper limb amputation provided stable, natural touch sensation in their [prosthetic] hands for more than 1 year … Patterned stimulation intensity produced a sensation that the subjects described as natural and without 'tingling,' or paresthesia. Different patterns produced different types of sensory perception at the same location on the phantom hand. The two subjects reported tactile perceptions they described as natural tapping, constant pressure, light moving touch, and vibration … Artificial touch sensation improved the subjects’ ability to control grasping strength of the prosthesis and enabled them to better manipulate delicate objects. Thus, electrical stimulation through peripheral nerve electrodes produced long-term sensory restoration after limb loss.
This work has obvious implications for traditional prosthetics, and its application in that regard should be both unlimited and uncontroversial, but there are eerier applications of the technology on the horizon.
As Rochester roboticist Kevin Warwick has demonstrated, prosthetics can be controlled remotely by way of direct neural interfaces; could these interfaces be similarly enhanced by recording physical sensations and conveying them in realtime to remote operators on the ground, allowing them to experience the prosthetic’s environment firsthand? Could sensor implants convey distinctive physical sensations to alert us to high levels of radiation, or the presence of dangerous levels of carbon monoxide in the atmosphere?
The answer to all of these questions is eventually going to be yes. Continuing advances in neuroprosthetics will inevitably give us the tools to compensate not only for our bodies' conspicuous limitations, but also for the ordinary limitations around which we’ve built our concept of what it means to be human. And once we have the power to expand our experience of the world, we’re likely to use that power to improve our understanding of our environments, protect ourselves and those we care about, and generally become more like the people we want to be. The prospect of advanced neuroprosthetics, like the prospect of transhumanism as a whole, is going to raise some very interesting—and, sometimes, very difficult—questions.
But in the more specific near-future context of medical and adaptive technology, most research into neuroprosthetics is likely to have a simpler goal: making life gentler and less frustrating for each other, when we are able to do so. And if we’re eventually going to have to approach the more outlandish implications of neuroprosthetics, that very decent, very human moral imperative is a good vantage point from which to approach them.