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IMAGINE trekking across the Sahara, popping in to see a friend in France, and admiring Niagara Falls, all without moving from your home. And what if you could do this despite being unable to move your limbs? For the first time, researchers have used fMRI 鈥� which detects your brain activity in real time 鈥� to allow someone to embody a robot hundreds of kilometres away using thought alone.

鈥淭he ultimate goal is to create a surrogate, like in Avatar, although that鈥檚 a long way off yet,鈥� says , director of the at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan. He is part of an international team that hopes to use this kind of technology to give healthy people and those who are 鈥渓ocked in鈥� 鈥� unable to move but fully conscious 鈥� the ability to interact with the world using a surrogate body.

鈥淭he team hopes to give people who are 鈥榣ocked in鈥� the ability to interact with the world鈥�

Teleoperated robots, those that can be remotely controlled by a human, have been around for decades. Kheddar and his colleagues are going a step further. 鈥淭rue embodiment goes far beyond classical telepresence, by making you feel that the thing you are embodying is part of you,鈥� says Kheddar. 鈥淭his is the feeling we want to reach.鈥�

To attempt this feat, researchers with the international used fMRI to scan the brain of university student Tirosh Shapira as he imagined moving different parts of his body.

Ori Cohen and Doron Friedman from the Advanced Virtuality Lab at the Interdisciplinary Center in Herzliya, Israel, and colleagues first took Shapira through several training stages in which he attempted to direct a virtual avatar by thinking of moving his left or right hand or his legs. The scanner works by measuring changes in blood flow to the brain鈥檚 primary motor cortex, and using this the team was able to create an algorithm that could distinguish between each thought of movement (see diagram). The commands were then sent via an internet connection to a small robot at the in France.

The set-up allowed Shapira to control the robot in near real time with his thoughts, while a camera on the robot鈥檚 head allowed him to see from the robot鈥檚 perspective. When he thought of moving his left or right hand, the robot moved 30 degrees to the left or right. Imagining moving his legs made the robot walk forward.

It takes a little while for the robot to register the thought. 鈥淭here is a small delay between the start of the neural activity and when we can optimally classify a volunteer鈥檚 intentions,鈥� says Cohen. But he says that subjects can adjust for this by thinking of the intended movement ahead of time.

Shapira took part in three trials, including one in which he was able to move the robot around freely and another where he was instructed to follow a person around a room at the French lab (see video above). In the third trial he successfully piloted his avatar to locate a teapot placed somewhere in the room. To test the extent of his feelings of embodiment, the researchers also surprised him with a mirror (see 鈥�On the inside, looking out鈥�). 鈥淚 really felt like I was there,鈥� Shapira says. 鈥淎t one point the connection failed. One of the researchers picked the robot up to see what the problem was and I was like, 鈥極i, put me down!'鈥�

The brain is very easily fooled into incorporating an external entity as its own. Over a decade ago, psychologists discovered that they could convince people that a rubber hand was their own just by putting it on a table in front of them and stroking it in the same way as their real hand. 鈥淲e鈥檙e looking at what kinds of sensory illusions we can incorporate at the next stage to increase this sense of embodiment,鈥� says Kheddar. One such illusion might involve stimulating muscles to create the sensation of movement (see 鈥�Feeling is believing鈥�).

The next step is to improve the surrogate. Replacing the current robot with the , made by in Japan, will increase the feeling of embodiment as it is roughly the height of an adult human and has a more stable and dynamic walk, says Kheddar.

The researchers are also fine-tuning their algorithm to look for patterns of brain activity, rather than simply areas that are active. This will allow each thought process to control a greater range of movements. 鈥淔or example, you could think of moving your fingers at different speeds and we could correspond that with different speeds of walking or turning,鈥� says Cohen, who presented the results of the embodiment trials at BioRob 2012 in Rome, Italy, last week.

So far, only healthy people have embodied the surrogate. Next, the researchers, along with Rafael Malach鈥檚 group at the Weizmann Institute of Science, in Rehovot, Israel, hope to collaborate with groups such as at the University of Western Ontario in Canada to test their surrogate on people .

鈥淚 think it is very impressive and in the broadest sense reflects where it is that we are trying to get to in enabling communication in patients who are deemed to be locked in or even vegetative,鈥� says Owen. He cautions, though, that there is a long way to go before the technology is able to provide long-term help for patients.

Electroencephalogram (EEG) technology, which uses electrodes attached to the scalp to record electrical activity in the brain, is likely to prove more practical than fMRI, he says, since it is cheaper and more comfortable to use for extended periods of time. Although EEG has been used to control robots, the readings are not yet as clear as those from fMRI. Nevertheless, this demonstration is 鈥渁n interesting glimpse of what might be possible in the future鈥�, Owen says.

If such surrogates were to enter the world, there are some challenges to consider. If it is not immediately clear who is controlling the robot, it could be extremely frustrating for someone interacting with it, says Leila Takayama at Willow Garage, a robotics company in California, who has studied the impact that telepresence robots have in the workplace. 鈥淚t鈥檚 a bit like when you share your Skype video feed with someone, but they don鈥檛 share theirs with you,鈥� she says.

鈥淚f such surrogates were to enter the world, there are some challenges to consider鈥�

Legal issues could also arise. If a surrogate were kicked in the street and broken, it鈥檚 the same as damaging someone鈥檚 property, says Noel Sharkey, a roboticist at the University of Sheffield in the UK. 鈥淗owever, if there was a way of the surrogate passing on the sense of touch to the person controlling it, that鈥檚 a different story.鈥�

For now, the team are hoping to develop the surrogate鈥檚 range of abilities. Shapira is keen to get back into the scanner to help: 鈥淥nce they add in the ability to hear people talk and speak back to them, then it gets to a whole new level of interesting.鈥�