The Brain as User Interface
From: IEEE Spectrum Online (08/02)
By: Samuel K. Moore

Recent breakthroughs have demonstrated that the brain can control prosthetic
devices. Research by neuroscientist John Chapin, Miguel Nicolelis, and others
showed that electrodes implanted within a monkey's motor cortex enabled it to
control a robotic limb; this prompted Arizona State University bioengineer
Andrew Schwartz to develop a coadaptive system in which a small number of
neurons in a monkey's brain are trained to direct the 3D movements of a
cursor on a screen. However, a major challenge of perfecting the technology
lies in converting feedback sensations felt by the prosthetic into signals
that the brain can translate. Chapin and colleagues at the State University
of New York (SUNY) have been exploring this conundrum with the development of
the roborat, an implant that allows scientists to direct the movement of
rodents by stimulating the parts of their brains associated with pleasure and
touch via electronic signals. To avoid the use of bulky current control
devices that would have made the experiment impractical, IEEE member Emerson
Hawley organized a simple transistor-to-transistor logic system that includes
a microcontroller and a battery-operated 433MHz radio. Chapin's project was
funded by the Defense Advanced Research Projects Agency (DARPA). The
effectiveness of the implant was tested last fall at the Southwest Research
Institute, where the roborats negotiated a maze of rubble, climbed trees, and
performed other activities. The tests showed that their movement through
tunnels inhibited radio transmission, but Chapin believes the problem could
be mitigated by creating a networked group of rats that would perform as
repeaters.  

http://www.acm.org/technews/articles/2002-4/0906f.html#item14
http://www.spectrum.ieee.org/WEBONLY/resource/aug02/brainimplants.html