Less than two decades ago, few could have envisaged a future where direct functional interfaces between brains and machines were commonplace. Today, there is a league of futurists, the transhumanists, that foresees an incredible expansion of human potential with the emergence of radical technologies that may one day enable our minds to be uploaded from biological brains and run on computers. As the borders between neuroscience, computer science and bioengineering fade, some of these predictions have already been realized. In fact, only a few years ago, Cathy Hutchinson, paralysed but mentally agile, became one of the first people to have her brain wired directly to a computer, allowing her to move a cursor, a wheelchair, and later a robotic arm with nothing but her mind.
This breakthrough in translational neural interfacing came with the founding of BrainGate (Cyberkinetics, Inc.), a neuromotor prosthetic system developed by Professors Donoghue and Hochberg in Duke University, who described Cathy’s control of the robotic arm as “a magic moment”. While it does indeed seem like magic that a mere imagination of action can result in the action itself, it’s actually quite straightforward. A sensor is chronically implanted into the part of the primary motor cortex that controls arm movements. The sensor detects electrophysiological activity arising from motor imagery in the brain, and transmits these signals to a decoder, which converts neuronal firing rates from simple reflections of brain activity into its intended outputs. Then, instead of controlling the muscles, which in patients like Cathy are usually damaged, the output is directed at controlling a computer, a robotic limb or a wheelchair, which puts into action the movement that was being imagined.
The leap from when the idea of neural interfacing was first conceived to its establishment as a field of neuroscience and engineering has been an enormous but impressively rapid one. The interest in this technology stems from its considerable potential to restore motor function, communication and even confer a certain degree of independence to patients suffering from severe neuromuscular disabilities. As the theoretical distinction between human and machine is gradually blurring, the untapped potential of interfacing looms large. It is likely that these systems will receive considerable attention in the future, but it is difficult to predict their various applications.
Indeed, there is an entire intellectual movement, transhumanism (abbr: H+) that is devoted to challenging the notion that the human condition cannot and should not be subjected to radical enhancements. Under this way of thinking, people with pacemakers, cochlear implants, prosthetics, or even artificial valves can be thought of as cybernetic organisms, or “cyborgs” – a blend of humans and mechanical parts. However, it is not so much this amalgam than the resultant interference with one’s behavior and personality that is worrisome. Take the example of a Parkinson’s patient treated with deep-brain stimulation, an invasive neural interface that aims to correct motor impairments through electrical stimulations to the subthalamic nucleus. Three years after the electrodes were implanted, this patient began to experience stimulation-related bouts of euphoria and unrestrained manic behavior. He bought houses he could not afford, incurred severe financial debts, and indulged in inappropriate sexual behavior towards nurses, all the while unaware of his deviant conduct. When the stimulation parameters were adjusted in an attempt to improve his manic condition, he returned to his usual state of competence, and regained his original capacity to judge “moral” behavior, although at the cost of deleterious effects on his motor abilities, thus leaving him bedridden. In this non-manic state, doctors considered him mentally proficient, and when given a choice, he opted to have the stimulator switched on again, and be admitted to a chronic ward in a psychiatric hospital.
Technological advancements are inevitable, and deep-brain stimulation is undoubtedly one that has had widespread success and improved the lives of over 30,000 people worldwide. However, in the wake of these exciting cutting-edge interfaces, we must consider the legal and moral implications of their effects on personality, most of which are still a matter of much debate within the scientific community. Who is to blame for seemingly involuntary acts by individuals whose brains appear to have been changed by machines? Is it the fault of the patient, of the doctor, or perhaps even of the computer? Can the behaviour even be considered involuntary if the patient, in a state of competence, chose to continue with the treatment that was itself the underlying cause of the behavior? Lastly, if this technology can be used to restore functions in those with disabilities, can it also be used to enhance or augment the existing capabilities of healthy people? And if yes, to what extent?