BOSTON — Neuroscientists are following through on the promise of artificially enhanced bodies by creating the ability to "feel" flashes of light in invisible wavelengths, or building an entire virtual body that can be controlled via brain waves.
"Things that we used to think were hoaxes or science fiction are fast becoming reality," said Todd Coleman, a bioengineering professor at the University of California at San Diego. Coleman and other researchers surveyed the rapidly developing field of neuroprosthetics in Boston this weekend at the annual meeting of the American Association for the Advancement of Science.
One advance came to light just in the past week, when researchers reported that they successfully wired up rats to sense infrared light and move toward the signals to get a reward. "This was the first attempt … not to restore a function but to augment the range of sensory experience," said Duke University neurobiologist Miguel Nicolelis, the research team's leader.
The project, detailed in the journal Nature Communications, involved training rats to recognize a visible light source and poke at the source with its nose to get a sip of water. Then electrodes were implanted in a region of the rats' brains that is associated with whisker-touching. The electrodes were connected to an infrared sensor on the rats' heads, which stimulated the target neurons when the rat was facing the source of an infrared beam. Then the visible lights in the test cage were replaced by infrared lights.
It typically took about four weeks of practice for the rats to figure out how to use their new infrared sensory system, but eventually the rats could respond to the invisible light as well as they responded to the visible light. Presumably, they could "feel" where the infrared flash was coming from, as part of their whisker-touching sense.
Nicolelis said the experiment showed that the brain is "much more plastic than we thought" when it comes to adapting to new stimuli.
That plasticity is the key to another set of experiments he and his colleagues have been conducting with rhesus monkeys, in which the monkeys learn to use their brain waves to control robotic arms or manipulate virtual objects on a computer screen. Over the years, Nicolelis' research team has developed a brain-cap system for monkeys that can pick up neural signals in almost 2,000 channels simultaneously, and send them wirelessly to a computer for processing. Nicolelis indicated that he was closing in on the goal of creating a system that could control a full-body exoskeleton.
"We can get animals to control the whole body now, when you get to the 1,000-neuron margin," he said.
Such work feeds into the Walk Again Project, a multinational effort to develop next-generation, full-body prosthetics for people with disabilities. Nicolelis wants to have an experimental brain-controlled exoskeleton ready in time to make its debut at next year's World Cup soccer finals, which are to be hosted by Brazil, Nicolelis' native country.
"We hope we will open the World Cup with a paraplegic young adult walking onto the field," he said.
Coleman, meanwhile, is working on ways to make brain-control devices less obtrusive. He is among several researchers who have been developing stamp-sized wireless sensors that can be worn like temporary tattoos. Such sensors can be used to monitor a person's medical signs — but if they're worn on the head, it's possible to pick up brain waves. In fact, Coleman found that the wireless tattoo sensors worked as well as the conventional, wired stick-on electrodes.
The results suggest that someday, it might be possible to develop a computer program to read the brain-wave patterns sent in by a tattoo on your forehead, and then fine-tune a virtual character to respond as if it was reading your thoughts.
The tattoos could have more down-to-earth applications in the medical field: In the future, such sensors could be used to monitor a newborn's brain for any signs of abnormality, or an older person's brain for signs of cognitive impairment.
"As we age, our ability to respond, or to modulate our attention to different new types of inputs, will start to slow down," Coleman said in a video interview distributed by AAAS. "Imagine if we could ... mount a sticker to the forehead that can provide quantitative outputs — measurements of that."
Does all this sound like a dream come true for the disabled, or a nightmare for folks worried about mind-reading robots? Feel free to weigh in with your thoughts in the comment section below.
More about the brain:
- Machine that feels is key to 'Jedi' prosthetics
- How scientists hacked into Stephen Hawking's brain
- Flash interactive: Road map of the mind
- Cosmic Log archive on brain science
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.