Giving a whole new meaning to hands-free cellphone use, neuroscientists at the University of California, San Diego, say they've discovered a way to dial a cellphone just by thinking of a phone number. Here, a guide to the mind-bending new study:

How does this brain-dialing work?
Researchers had users sit in front of a screen displaying a keypad. The numbers on the keypad each flashed at a slightly different frequency. Special electrodes attached to the users' scalps detected those frequencies and relayed the brain activity to a cellphone equipped to decode the signals. In the end, users could "dial" just by thinking of a number on the screen. The study was published in the Journal of Neural Engineering.

Would the interface work for anyone?
Yes. "From our experience, anyone can do it," says researcher Tzzy-Ping Jung, as quoted in Technology Review. But getting the system to work well "takes some practice, and some people are better at it than others," says Mike Masnick at TechDirt. Of the 10 subjects asked to dial a 10-digit phone number, seven of them reached 100 percent accuracy. But Jung himself only succeeded around 85 percent of the time.

How could this technology be used?
"The device wouldn't just be cool — it would also be a great advantage for people with disabilities," says Marina Watson Peláez at Time. Other cellphone users could have "the ultimate hands-free experience," or the system could be adapted "to detect when drivers or air-traffic controllers are getting drowsy by sensing lapses in concentration," says Duncan Graham-Rowe at Technology Review.

Could this really work on regular cellphones someday?
There may be obstacles. A system like the one used in this study requires "a large visual stimulus," according to Eric Leuthardt, director of the Center for Innovation and Neuroscience Technology at Washington University, as cited in Technology Review. A small cellphone display might not be enough to create the necessary visual response. But if this kind of system does become reality, says Masnick at TechDirt, "I'd sign up."

Sources: Daily Mail Mashable, Tech Dirt, Technology Review, Time