Neural prosthetic interfaces with the nervous system.

Once damaged, the adult mammalian nervous system is capable of little functional regeneration. Thus, clinical disorders such as deafness, blindness and paralysis have been treated primarily by substitution rather than correction (e.g. teletype for telephone, braille for print, wheelchair instead of walking). However, recent advances in the technology of miniature electronic implants and in the basic understanding of sensory and motor functions have made it possible to build neural prosthetic devices that work by exchanging information directly between computing devices and neurons. Such interfaces are already permitting thousands of otherwise deaf patients to hear sounds directly; some have appreciable speech comprehension without visual cues. There is active research on restoring many types of sensory, motor and autonomic function. Two interesting synergies have emerged. The first stems from the recognition that the biophysical processes involved in stimulating and recording from neurons are universal; thus, technical advances have broad implications in many clinical areas. The second stems from the unique opportunity that such prostheses present to conduct neurophysiological and psychophysical studies directly in conscious human subjects.