An armband loaded with 28 tiny electrodes could help amateur guitarists learn to play like pros. The device, called PossessedHand, sends pulses of electricity through the skin and into the nerves that power the fingers. And by varying the timing and intensity of the shocks, it could help beginners channel their favorite rockers -- dead or alive.
PossessedHand is still under development by scientists at the University of Tokyo and Sony Computer Science Laboratories. It's not the first gadget to move muscles using electricity -- similar devices have been approved by the U.S. Food and Drug Administration to help people with paralysis. But because PossessedHand can bend several joints simultaneously or in sequence, it could be the first to coax fingers into tackling a tune.
"What's novel about this is they can control finger movement at multiple joints at the same time, and then program when those movements occur," said Dr. Preeti Raghavan, assistant professor of rehabilitation medicine at NYU Langone Medical Center.
The result, PossessedHand developers say, is a series of movements that could help people learn to strum a song. But some musicians argue that learning to play an instrument takes more than a flick of the fingers.
"While it looks very innovative, and I'm a big fan of science, music really is a human experience and there's no way around that," said Dan Smith, a New York City guitar teacher. "Making music is a mindset that goes beyond putting your fingers in the right place."
But getting those fingers in the right place -- especially the pinky -- for many, isn't easy.
"You know your hand, and you have to experiment with what works," Smith said. "There's no one right way to do it. There are just ways that, generally speaking, tend to work best."
The signals that move the muscles normally come from the brain. But when a stroke or spinal cord injury causes a break in the neural circuitry, the same nerve-stimulating technology tapped by PossessedHand can help people move an otherwise paralyzed limb. The devices currently available, however, fall short when it comes to power and coordination.
"As the flexor muscles of our hands contract, the extensor muscles relax, and all the other surrounding muscles tense or relax to support the movement," said Dr. Brian Greenwald, assistant professor of rehabilitation medicine at New York City's Mount Sinai School of Medicine. "There's an amazing orchestration that occurs when we're flexing our fingers or our wrist. And it's that orchestration that gives us power."
Greenwald said he's surprised PossessedHand could stimulate individual nerves from outside the arm -- a feat that he's only seen accomplished using electrodes implanted under the skin.
"The skin wants to keep things out, and it does a good job of that. To overcome the electrical resistance in the skin, you would have to turn up the voltage you use." And that, Greenwald said, could get uncomfortable.
Nevertheless, the days of electric guitar plucking, and better aids for people with paralysis, could be on the horizon.
"Who would have thought 30 years ago that I'd have 2,000 songs in my pocket," said Greenwald, referring to his iPod. "Like John Lennon said, I'm a dreamer."