So it turns out a bit of mind control might be possible after all.
Scientists had already shown that a human could send an electronic brain signal to a rat, prompting it to wiggle its tail. Now, two University of Washington researchers say they have demonstrated that one person's thoughts can control another person's movements.
First, they placed electronic probes against their heads. Then one man looked at a computer game on a screen and thought about what move he wanted to make. Sure enough, the other man, who was across campus with no view of the screen, almost instantaneously moved his right index finger to make that move. He said it had the sensation of a nervous tic.
"I felt a bit like Alexander Graham Bell working on the first telephone," said Rajesh Rao, the computational neuroscientist whose brain sent the signal.
Although the scientists acknowledge their work is still in rudimentary stages, they say it suggests a future where people may one day be able to communicate directly brain-to-brain. In the past two decades, neuroscientists have made dramatic advances in connecting human brains with computers, largely in the hope of helping disabled and paralyzed patients communicate with others and operate prosthetic limbs.
"We have demonstrated the first human brain-to-brain interface for a very simple form of transfer of information," Rao said. Moreover, the prior brain-to-brain interfaces involved electrodes implanted directly into rat brains, "so this is the first noninvasive brain-to-brain interface as well."
"It felt a bit surreal," Rao added.
The scientists cautioned this system only reads very simple brain signals and not thoughts.
"I've always been a fan of 'Star Trek,' but we're not really at the point of the Vulcan mind meld yet," Rao said. "The engineering has a long way to go before we can demonstrate anywhere near the kind of brain-to-brain interfaces seen in science fiction."
"It's also a completely voluntary process, so there's no specter of mind control in secret," Rao added. "You can't read somebody's mind or move somebody's body without them knowing about it -- they both have to have devices on or against their heads."
Neurobiologist Miguel Nicolelis at Duke University, who in February reported he and his colleagues linked two rat brains together intercontinentally, said this latest research was rudimentary at best. "This is more like one brain sending an electric shock to another than a true interface," Nicolelis said. Researchers at Harvard University followed with their human to rat experiment, announced in April.
In their Aug. 12 experiment, Rao wore a cap studded with electrodes that read electrical activity in his brain while he played a simple video game with only his mind. Each time he was supposed to hit a button to shoot a cannon at a target, a pirate ship, he imagined moving his right hand, although he was careful to not actually move it.
His colleague, cognitive neuroscientist Andrea Stocco, sat in a lab a quarter mile away, with a powerful magnetic coil against his head in the area of the left motor cortex, which controls motions in his right hand. Rao's brain signals were transmitted over the Internet to a computer that prompted the magnetic coil to stimulate Stocco's brain, causing him to move his finger. By the final session of the experiment, Rao successfully hit all the targets with each attempt.
Rao said the researchers now "want to see if we can extract and deliver more complex forms of information from one brain to another," Rao said. "Ideally, we can have a two-way form of communication instead of the one-way flow we have now, for more of a conversation between brains."
They plan to conduct the experiment with more subjects to confirm the result and submit their findings to a scientific publication for review.
In the meantime, Rao said they wanted their research, which the University of Washington announced Tuesday, to raise questions about the implications such technology could have.
"One can imagine a future where information can be conveyed from one brain to another nonverbally," Rao said. "We've all had a mathematics teacher who was bad at conveying ideas but good at solving problems -- maybe in the future that kind of knowledge can be delivered directly instead of verbally. What does that mean for humanity? What kind of ethical and moral issues does that raise? We want to bring those issues up to the public before the technology runs too far ahead."
Nicolelis said he and his team are now linking monkey brains together "to see if they can collaborate, using the interface to exchange information, working together to solve a common task. We did that with rats, and now we want to take it to the next step. We want to study this in animals first before taking the leap to humans."
"We're very interested in seeing if networks of brains can solve problems a conventional computer cannot (and) lead to emergent properties we can't even predict now," Nicolelis added.