Seite - 74 - in Cyborg Mind - What Brain–Computer and Mind–Cyberspace Interfaces Mean for Cyberneuroethics

74 • Cyborg Mind Neurorehabilitation The use of neuronal interface systems is also being considered to help persons regain or relearn motor functions when these have been limited by disease or injury.124 Such interfaces, which are usually associated with a computer, use the individual’s own muscles or body part, instead of a machine, to initiate an action. Spinal Neuronal Interface Systems A driving impetus behind much of the work of researchers in feedback sys- tems is the desire to find new ways of restoring movement to people whose spinal cord has been injured through an incident like a car crash or a sport- ing injury. In this tragic situation, a person has perfectly healthy leg muscles, with nerves running right up to and connecting with the spinal cord, but no signal reaching them. Consequently, the muscles waste away, not because they are damaged, but because they are not used. In theory, it seems a straightforward task to build a feedback neuronal interface system that could bridge the injury and get the person walking again. First, the system would need to pick up the nerve traffic with elec- trodes inserted into the working end of the spinal cord. A computer would then filter the signal and detect the traffic triggered by a person’s mental com- mands to the leg muscles. These signals would finally be fed to the nerves that remain connected to the muscles to operate the leg and foot. The subject would also be able to use feedback, such as watching the legs move and assessing whether they are balanced, to modulate neuronal activity on an ongoing basis. As a result, the movement that the subject is aiming for can be adjusted, promoting learning and increasing accuracy. Such a system was considered in the United Kingdom in 1994, when a team of scientists implanted electrodes into the spine of Julie Hill, a woman who had been injured in a car crash.125 They were then able to collect her brain signals and feed them to her muscles through computer-driven tech- nology. After hours of exhausting testing and training, she was able to stand moderately stable, but could not begin walking. In order to eliminate the problem of balance, the team moved Hill to a sitting down tricycle. By 1997, she was able to train herself and the system to enable her legs to push the pedals in order to power the bike. In many ways, this early attempt of what is sometimes called ‘functional electrical stimulation’ was a success. But Hill’s equipment proved too cumbersome to use and she has now become accustomed to life as a non-walking person. This experiment demonstrated that inserting electrodes and picking up spinal traffic through filtering the nerve impulses, so that individual nerves This open access edition has been made available under a CC-BY-NC-ND 4.0 license thanks to the support of Knowledge Unlatched. Not for resale.