Regarding the prosthetic hands, you can not beat the Luke Skywalker receives in The empire against attack . Not only will this robotic arm allow him to wield a lightsaber with great dexterity, each finger twitched when their robot thicket. Although real life prostheses controlled by the brain that allow a person to, say, pick up a pencil to continue to improve for amputees, members can actually feel tactile sensations remained a challenge. Now, by implanting electrodes in the motor and sensory areas of the brain, the researchers created a virtual prosthetic hand that monkeys control using only their minds, and enables them to feel virtual textures.
neuroscientist Miguel Nicolelis University Duke in Durham, North Carolina, whose group developed the so-called brain-machine interfaces, said that one of the traps in these systems is that "no one has been able to close the loop "between the control and feel of a member physical contact. So he and a group of researchers decided to create a "brain-machine-brain" interface using a virtual system. The researchers implanted two sets of tiny electrodes into the brain of a monkey: a set in the motor control center, and the other in the part of the somatosensory cortex that processes the sensation of physical touch of the left hand. Using the first set, the monkey could control a virtual monkey arm on a computer screen and sweep hand on virtual disks with different "textures". Meanwhile, the second set of electrodes supplied a series of electrical pulses in the touch center of the brain. A low pulse rate indicates a rough texture, while high frequency indicated a fine texture (see video), and monkeys quickly learned to tell the difference.
By giving the monkey rewards when he identified the right texture, the researchers found that it took as little as four training sessions for the animal to systematically distinguish the textures of each other, even when the researchers switched the order of visually identical discs on the screen. The researchers then implanted electrodes in the sensory area which receives the tactile sensations of the foot in a different monkey; this monkey, too, acted as if the virtual appendage (in this case, the foot) was his own, moving it to identify the textures correctly, reports the online team today Nature .
Although the monkeys are all adults, motor and sensory regions of the brain are remarkably plastic, Nicolelis said, the combination of seeing an appendix they control and feel a physical touch turns thinking the virtual appendix their own "in minutes." And throughout this experience, literally General touch the monkey does not seem to be affected. "The brain," Nicolelis said, "is the creation of a sixth sense."
"It is certainly an important step in brain-computer interfaces," said neuroscientist Sliman Bensmaia of the University of Chicago, which develops tactile feedback human prostheses systems. Too robotic arms under development, even very advanced, he said, ignoring the importance of touch. "Sensory feedback is critical to anything," he said. Even mundane tasks like picking up a cup require a lot of concentration so that the wearer does not drop or crush.
The new work is still an early stage, however, he said. A biological arm receives innumerable not only texture entries, but also on the temperature and position in space.
Nicolelis said his group is working to refine the sensory evaluations and to explore ways to link the brain and the wireless computer. After many years working on brain-computer interfaces, he said, "we get very close to the place where they can be clinically useful" for paralyzed patients, not only in the laboratory, and also for physicians. touch feedback can enable surgeons, for example, to perform microscopic surgery or countless other applications. "the brain," Nicolelis said, "has evolved capabilities that go far beyond the body."
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