Neuroscientist John Donoghue of Brown University has brought us a big step closer to the day when people can interact with computers directly through the power of thought. In July he and his team published a paper in Nature outlining remarkable progress in picking up brain signals with implanted electrodes and using those signals to control a range of devices.
The experiments were conducted on a 25-year-old Massachusetts man paralyzed from the neck down. In 2004, surgeons placed a tiny 100-electrode array in his primary motor cortex, the brain region that controls voluntary movement, to collect electrical impulses from nerve cells and send them to a series of signal processors. Donoghue and his colleagues then supervised as the computer translated the man's thoughts of moving his arm and hand into the actual movement of external devices. On the first day the system was up and running, he was able to master the technique. He could move a computer cursor, play a video game, open e-mails, draw a crude circle, operate a television remote control, and even move a prosthetic hand and arm—using nothing other than his will.
The same basic brain-computer interface system had been tested earlier in monkeys, and a group in Georgia implanted electrodes in people as far back as the 1990s. But no other group has used implanted electrodes to monitor so many human neurons at once or had such impressive results.
The system was removed from the original subject after 14 months. It is now being tested on three other patients, including one with ALS. Neurologist Leigh Hochberg, the lead author on the paper with Donoghue, hopes that the current trials are the first step toward giving severely disabled people an unprecedented degree of independence. "The participants in these trials are pioneers," he says.
