Remarkable Man-Machine Interactions
Dr. Silvia Helena

Since the times of Aristotle, man has noted with awe the many parallels existing between organisms' biological organization and that of machines. In fact, for centuries we have been bestowing to our creations many of the abilities and functions of human beings. Shovels are extensions of our arms, cranes are fingers to grab heavy objects, water pipes are similar to our system of veins and arteries, telescopes increase our eye power; and, nowadays, the internal wiring in computers is almost as complex as our nervous system.

The integration between man and machine is also increasingly common, particularly in the field of medicine. Let us observe for example, artificial implants. For many years, man has been using mechanical prosthesis with hinges that imitate the working of our articulations as for instance, artificial knees. Artificial heart valves are also common place devices which have been surgically implanted to save hundreds of thousands of lives. We use our artifacts inside our own bodies, and the distinction between what is natural and what is artificial is becoming more and more fuzzier.

In the last years, the technological frontier for man-machine integration has been the nervous system. A large proportion of the progress that has been occurring in the field of biomechanics, robotics, and neuroprosthesis is the result of intentional design: a growing field named as bionics, or the engineering of devices that imitate biological functions. In the same manner that a computer send orders through its cables and connections, electrochemical impulses travel through nervous fibers until they reach each organ of the body. By imitating this natural transmission system, scientists are able to correct faulty sensorial and motor processes, such as deafness, blindness and paralysis, by means of electronic microchips that can be used either to stimulate cells or to control biomechanical prosthesis. In this manner, complex microchips implanted in the body or the brain are substituting cells that don't work well or that are lesioned, as well as to stimulate muscles or nerves.

With artificial cochlea, for example, deaf persons say that they can hear again. However, Dr. Merzenich, a neurophysiologist from the University of California at San Francisco, says that "actually, these inputs to the brain are distorted. What seems to happen is that the brain somehow adjusts its connections in order to make sense out of the inputs it receives". This clear demonstration of plasticity in the human brain leads to the hope that scientists will be able to develop other similar feats in the future. One of these could be artificial members provided with "electronic neurons" capable of responding to signals sent directly from the brain.

By bestowing intelligence to machines, man will eventually be able to acquire many benefits for his health, as well as to increase his own intellectual capabilities, such as memory. The limit of this symbiotic process is unforeseeable. Today, neurotechnology is able to substitute and to control simpler sensory and motor functions. The question is: will it progress to the point that cognitive processes will also be substituted ?

Silvia Helena Cardoso
Editor-in-chief and Founder