It sounds like science fiction, but scientists around the world are getting tantalizingly close to building the mind-controlled prosthetic arms, computer cursors and mechanical wheelchairs of the future. Researchers already have implanted devices into primate brains that let them reach for objects with robotic arms. They've made sensors that attach to a human brain and allow paralyzed people to control a cursor by thinking about it. In the coming decades, scientists say, the field of neural prosthetics - of inventing and building devices that harness brain activity for computerized movement - is going to revolutionize how people who have suffered major brain damage interact with their world. The joint UC Berkeley and UCSF center started a year ago to take advantage of the neurology expertise in San Francisco and the engineering skills across the bay. Such devices that allow the brain to control a device aren't entirely new. Aside from some small steps made at other institutions - the brain-controlled computer cursor, for example - there's the cochlear implant, the first neural prosthetic tool developed and the only one that's ever seen wide use. The cochlear implant, which was invented at UCSF in the 1970s, intercepts sounds as electrical signals and then sends those signals directly to the brain, bypassing the damaged nerves that caused hearing loss. The devices being developed today work under the same premise but are much more complex. Over the past decade, scientists have made leaps of progress in learning how to read and decode the millions of electronic impulses that fire between neurons in the brain, controlling how our bodies move and how we see, feel and relate to the world around us.
It's not enough just to prompt the right muscles to move an arm. Millions of signals in the brain help us determine where our own arm is in relation to our body, so our hand doesn't grope wildly for the glass. Our brains sense that it's a delicate glass that must be picked up carefully, pinched between fingers. The neurons control how fast our arm moves, making sure the wine doesn't slop over the edges. That's an astronomical amount of communication happening, all in fractions of a second, without our even being aware of it. In fact, it's more communication than our best smart-phone technology can handle. The neural prosthetic devices that are just in their infancy now work by connecting a device inserted into the brain directly to a computer. The signals from the brain, in the form of electrical impulses, travel through a cable to the computer, where they are decoded into instructions for some kind of action, like moving a cursor. But for a neural prosthetic device to actually be useful, it would have to be transplanted near or in the brain and transmit wireless signals to a device like a robotic arm. It would need to be able to last forever - or at least a lifetime - on batteries that never have to be changed and won't damage the brain.Other problems are going to require an even deeper understanding of how the brain works. Scientists don't yet know what parts of the brain would be best suited for implanting a device to read electrical signals - or even whether an implanted device would work better than one that's attached to the brain's surface. It's possible that a surface device could collect enough information to be useful in controlling a neural prosthesis with much less risk to the patient.
More information:
http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2011/12/27/MNHU1MDLEU.DTL
More information:
http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2011/12/27/MNHU1MDLEU.DTL
