Science Articles

Beyond the Body: Neuroengineering

Wed, 29th Sep 2004

Barry Gibb

Artificial limb: An illustration of an artificial hand by Jean le Royer, Paris 1564. Courtesy of the National Library of Medicine. The alarm goes off. You stick the kettle on, put on your favourite CD then check out the weather and traffic. Everything is normal, but for the fact that you haven't even opened your eyes yet. Until recently, the brain's job description was limited to controlling its immediate owner - you. Now, it seems we are on the brink of being able to extend the mind's reach, moving it beyond the body. Welcome to the world of neuroengineering.

The notion of connecting your mind to a mechanical interface may seem bizarre, far-fetched or even slightly scary. But we do it all the time; in fact, I'm doing it right now. As I type, I'm using a keyboard as a mechanical interface between my mind and the computer - an extension.

However, new advances mean that machines and computer hardware will be able to interface with the human body, directly, at a biological level. But, for a moment, ignore your healthy fear of mad cyborgs and mind control through secret implants. Let's concentrate on reality: what technology currently exists, how it is being used, who funds this work and how it might ultimately be used. Are we ushering in a golden age of human evolution or laying the foundations of disaster?

There are two major levels that biological interfaces are being applied: peripheral, such as prosthetic limbs, and neural, whereby a special computer chip is placed directly into contact with the brain. Let's start at the periphery.

Imagine a portion of a limb has been lost, up to the elbow, for example. Doctors must now work with the remaining tissue to try and help the person regain use of that limb. Somehow, they need to be able to get messages from the brain to the tips of a new electronic arm. But the signals from the brain are now only getting as far as the upper arm. How do the doctors bridge the gap?

To do this they can use an ingenious device called a myoelectric prosthesis. By attaching this advanced robotic arm to the existing tissue, the device is capable of detecting small contractions in the remaining arm and turning those contractions into an electrical signal that will then move the new arm in a specific manner. By learning how specific contractions cause specific movements, the user can teach the synthetic arm to move. We're talking state-of-the-art here, but it would still take months to master. However, this too might be about to change, with the introduction of 'evolvable hardware'.

Fernand Desmoulin's portrait entitled L'Operation, 1897. Courtesy of the National Library of Medicine.A new type of computer chip designed by Isamu Kajitana at the University of Tsukuba, actually learns what the user is trying to do with their muscles. It then modifies itself until the most efficient way of interpreting that information is reached. A bit like playing chess against someone who wants you to win; you barely need to think about the game and it's over in a few moves.

That brings us to the Holy Grail of interfacing - the human brain. Wouldn't it be better if you could take signals directly from the brain, your very own supercomputer, and turn those pure, core signals directly into movement - exactly what it does naturally.

The thing is, your entire body is an interface for your brain. Your hands, eyes, skin; they are all part of a system brought into being by the process of evolution. Your eyes are an interface between light bouncing off the world around you and the wonder of vision. Your skin is an interface between your insides and the world, sensing the environment.

A recent breakthrough in brain-interfacing described research in which monkeys controlled a robotic arm with thought alone. Usually, this is the stuff of sci-fi; but it is real and it is incredible. How've they done it?

Everything you do depends on signals from your brain. Think of the opening sequence of the movie, Fight Club. Here, we actually get to see 'fear' travel through the brain. It's as if your brain has an ultra sophisticated map inside, composed of nerve cells, all giving directions to what makes you, you.

Drink a glass of water and you light up all of the nerve pathways that are responsible for drinking water (filling a glass, picking the glass up, pouring the water in your mouth, putting the glass down). Laugh at Ricky Jervais and all the paths that are involved in humour and laughter shoot off. Every single action that you perform, and importantly, every thought you think, uses specific patterns of activity in your brain.

Brain2: Inspired by the thought of brain-technology fusion? Courtesy of Barry J Gibb, copyright 2003.What if you could master this mind-map, learn exactly how to get from drinking to laughter to movement. Miguel Nicolelis, Duke University, North Carolina, is one of the scientists heading this field, called neuroengineering. By having a special piece of hardware connected to two monkey's brains, Miguel and his colleagues were able to record the brain pathways fired when the monkeys were controlling a joystick. This joystick was moving a robotic arm in the next room that the monkeys could see, whilst they tried to move it towards a target. This enabled the scientists to see precisely which brain signals caused forward, back, left and right arm movements.

The scientists then removed the joystick. Initially, the monkeys waved their hands around to try and get the robot arm to move where they wanted. However, in a jaw dropping moment, one of the monkeys realised that it did not have to move at all. By simply thinking about moving the robot arm, it fired the correct path in its brain, which passed the information to the implanted hardware, then to the robot arm.

The benefits of this fascinating work will surely have far reaching consequences for people who have lost limbs or are paralysed. But what else? Much of the work concerning the blossoming field of neuroengineering is funded by DARPA, the US Defense Advanced Research Projects Agency. And boy, do these guys have dreams!

If you want ambition, how about the notion of a fighter pilot being able to control his craft by thought. As an extension of his body, with zero response time. Not enough? How about said pilot being overridden by a chip in his head, should he make a mistake (these planes are expensive!). Still not happy! Remember that immortal line from The Matrix, "I know kung fu." Well, you guessed it; scientists such as Ted Berger at the University of Southern California even think it conceivable that we could implant instructions into neural chips that would allow soldiers to perform actions that they have not learnt by conventional methods.

As always, advances in technology can be a double-edged sword. Benefits from these emerging technologies are sure to revolutionise the quality of life for many and thoughts of cybernetic soldiers are currently the stuff of fantasy.

For the present time, sticking on a CD or driving your car can only be achieved using the most advanced piece of engineering known to science, you.

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