Scientists "Drive" Rats By Remote Control

Ben Harder
for National Geographic News
May 1, 2002
Next time you see a rat scurrying across the room, beware, it might not be as innocent as it seems. It could be a remotely operated robo-rat working for an intelligence agency.

Scientists have trained rats to respond to signals from a laptop-based command center up to 500 yards away, enabling a human operator to remotely guide the robo-rats through an obstacle course. Intelligent, nimble, and inexpensive, such guided animals could be used for spying or on dangerous search-and-rescue missions.

Remote-controlled animals could take the place of human workers in performing dangerous or difficult jobs such as locating survivors in collapsed buildings or clearing fields of hidden landmines, said Sanjiv K. Talwar of the State University of New York.

Other uses might include pest control, military surveillance, and mapping of underground areas, said Talwar, who led the team of neuroscientists that developed the application.

In recent years, robotics researchers have been developing purely mechanical machines that may someday be capable of handling such tasks, but the newly developed, electronics-toting robo-rats could be practical anywhere robots might be useful, Talwar said.

While robots need to be precisely programmed to correctly complete even the simplest task, he noted, rats are naturally capable of performing many actions that would be required of, for example, search-and-rescue machines.

"You give [rats] a command, and they have their own sort of native intelligence to carry it out," Talwar said.

Another benefit of using animals as platforms for robotics is that they provide inexpensive, organic substitutes for much of the hardware that machines with similar functions would require.

For the initial experiments, for example, the microprocessor, receiver, and antennae needed for each rat cost no more than U.S. $40, Talwar said. Adding video cameras and satellite navigation equipment would increase that basic cost, but would still add up to far less than the price tag on a robot with similar capabilities, he said.

Virtual Cues and Rewards

The navigation system of a robo-rat takes advantage of the rats neurological system, which is wired to learn appropriate responses to stimuli sent to it in the form of electrical impulses. By training the rats to respond in particular ways to particular stimuli, the researchers were able to effectively program the animal to act out remote commands.

The researchers first threaded three wires as narrow as human hairs into each rats brain and attached them to a microprocessor slung on the rats back like a backpack. Two wires served to deliver electrical cues—one each to the brain cells associated with the rats left and right whiskers, respectively. A third wire doled out rewards to a separate area of the brain.

Then a member of the scientific team, using a laptop computer, remotely stimulated the microprocessor to send an electrical signal through one cue wire or the other. The rat "felt" a touch to the corresponding set of whiskers, as though it had come in contact with an obstacle.

If the rat responded by turning in the desired direction, the controller encouraged the animal with a brief electrical pulse to its brain's reward center. The rat would feel a sensation of pleasure.

This pattern of stimulus and response is parallel to the way that a shepherd might train his sheepdog, Talwar said, "except the rat will not work for love." Instead of offering an encouraging scratch behind the ears, Talwar's technique creates a world of "virtual cue and virtual reward" in which the rat learns to respond to the remote orders rather than rely on its own instincts, he said. The animals demonstrated an impressive ability to learn and remember how to interpret remote commands. It took no more than ten sessions to train the five animals the researchers used.

After training, some of the rats were retired for up to half a year before once again being outfitted with microprocessors and wires. They still responded readily to orders from the laptop.

Guided Animals

Once the rats were trained, the scientists piloted them through a gauntlet of tests.

"We were able to guide rats in systematically exploring large, collapsed piles of concrete rubble, and to direct them through environments that they would normally avoid, such as brightly lit, open arenas," the researchers wrote in the paper in which they presented their work, which appeared in the May 2 issue of the journal Nature.

The development of the robo-rat grew out of earlier work that Talwar and his colleagues had done on brain-machine interfaces. One project had enabled a rat to move a robotic arm merely by thinking about it. Talwar hopes that this technology can be applied to help disabled people manipulate machines that can serve them in the place of lost or paralyzed limbs.

After September 11, Talwar said, he and his colleagues saw that there might be other useful applications for their technology.

Talwar acknowledged that some people—including himself—feel somewhat uncomfortable with the notion that animals can be remotely controlled. "The idea sounds a little creepy," he admitted.

Nevertheless, he noted, the rats don't suffer because they receive only "reward" neural feedback, never negative stimuli. And, Talwar said, "there is no cruelty" involved in operating robo-rats because the animals are never intentionally killed or harmed.

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