Tuesday, December 07, 2004

Thought and Action

It's an amazing day for neurotechnology. Via Engadget, check out this amazing story on the BBC: researchers from SUNY Albany & New York State's Wadsworth Center have demonstrated an electrode-cap system that converts the wearer's thoughts of controlling a cursor into actually controlling a cursor.

The researchers are Jonathan Wolpaw and Dennis McFarland, and they've published their results online with the Proceedings of the National Academy of Sciences--and their research report is publicly availaible. They describe their set-up as requiring EEG data from "64 standard electrode locations," which was then digitized and fed to a computer. The four subjects, two of whom are paralyzed but have normal arm-movement, wore the caps and faced a screen. A "target" appeared on one of 8 spots at the edges of the screen, one second later a cursor appeared in the center of the screen, and the person wearing the cap had only 10 seconds to move the cursor to the target. If they succeeded the target "flashed as a reward" but if they failed, it simply disappeared.

The signals from the cap were translated to the control of the cursor in an amazingly straightforward way, simply combining amplitudes from two types of brainwaves (mu waves at 8-12 Hz and beta waves at at 18-26 Hz) in linear equations for the horizontal and vertical directions, and adjusting the weights on those equations for each participant with an adaptive algorithm. You can download a Quicktime movie of one of these sessions here. Watching the little pink targets practically crash into their targets one after the other is mesmerizing.

The possibilities for people suffering from spinal cord injuries are inspiring, and in general mind-boggling. This doesn't seem like it should be a very expensive set up--its non-invasive and is built from existing, fairly common technology. It wouldn't take a lot to attach cursor-movement to a remote-controlled car, for instance, or a pen. I predict an eventual market for everyday objects equipped with WiFi-controlled motors.