In the last few years a small piece of science-fiction has become science-fact. In a recent study a woman, paralysed from the neck down, was able to move a robotic arm using only the power of her mind. Through this robotic appendage she was able to do something she hadn’t done for many years: pick up a cup of coffee and drink from it out without help.
This life changing feat was achieved through the surgical implantation of a computer chip within her motor cortex (the area of your brain which activates when you initiate a movement). The chip detected activity within this region of the brain, forming what is known as a ‘neural interface’. This chip was then connected to a computer which controlled the robotic arm. After some practice, the participant’s brain adapted to the neural interface allowing her to control the arm. What makes this amazing is that despite being paralysed for 15 years, only 20 minutes of adaptation was needed to manipulate the arm adequately.
This research is the latest in a long line of studies showing how machines or devices linked directly to the brain (so called “neuroprostheses”) can be controlled by thoughts alone. First pioneered in rodents and monkeys, this technology is now showing promise for improving the lives of many handicapped people. Potentially, anyone suffering from paralysis in the future will be able to regain a degree of independence and control over their surroundings.
These interfaces also have scope beyond treatment of paralysis, they have in fact been applied to the treatment of many different disorders. A few examples include: Locked-in syndrome, a state where a person is completely unable to move or signify that they are conscious. These patients are unable to speak or in some cases even blink. Trapped in a prison of their own body, patients have gone years before anyone has known that they are conscious. Thankfully, neural interfaces have been developed that allow direct control of a cursor on a computer screen and control of text selection systems for communication. For these people, neural interfaces will provide an outlet through which they can communicate with and interact with the outside world. Similarly, a neural interface in the visual cortex connected to a camera has enabled blind subjects to regain some of their sight. Although sight is only restored to a level that allows them to perceive the outline of shapes and to read, this is still an amazing breakthrough.
Taking the research further, the ‘Holy Grail’ would involve a neural interface coupled with muscle stimulation (a therapy already in use). This would give the patient direct control over their own limbs; providing what could be described as a substitute nervous system which could bypass the injury causing the initial paralysis. Although such complex limb control is still just an ambitious long term goal, more basic control is already within reach and is currently being implemented.
And what about amputees? There are already advanced mechanical prosthetic limbs that can be controlled by muscle movements. One example is shown below:
However, whilst the control and range of motion of these hands is already sophisticated, a direct neural implant would provide numerous advantages in the complexity of movement as well as the ability to perceive touch, temperature and position. Were all of these incorporated into a neural interface, a prosthetic limb would feel more like a new arm or leg rather than simply a mechanical appendage.
Of course in fiction, people with neuroprosthetic implants are often depicted as psychotic transhuman abominations bent upon the destruction or corruption of normal society. But, given the brain’s incredible ability to adapt, what sort of non-therapeutic implants should we realistically consider? What if instead of recovering some form of lost function, neural interfaces were instead used by healthy people to gain some new function? For example, what about a new sense? Birds can navigate thousands of miles across featureless ocean by intrinsically perceiving the earth’s magnetic field. If there was a compass in your head that was always on and as easy to interpret as your sense of hearing, you might never get lost again. What if a neuroprosthetic implant allowed you to perceive sounds beyond the normal range of human hearing, like a supercharged hearing aid? Or perceive light beyond the normal range of human vision in conjunction with eye augmentation? You then quite literally would have x-ray vision.
Precisely how neural implants will develop in the next few decades is difficult to predict. Significant technical challenges exist in the long term function of these devices and their ability to resist problems such as tissue deterioration, movement and the body’s own immune response. Despite these issues, they undoubtedly will play a huge role in the lives of people with debilitating injuries, but how much of a role will they play in the lives of the rest of us? We will simply have to wait and see.
Post by: Chris Logie