The sixth-sense prosthetic could be used for shoring up the first five: If a tumor damages the visual cortex at the back of the brain, the primary sensory cortex on top—still thought by many neuroscientists to be inalterably hardwired for touch—might be commandeered to process incoming visual signals. The Duke researchers have begun to do similar experiments with howler monkeys.
The device can also explore possibilities for brain enhancement. The rats, Nicolelis says, seemed to be developing a new form of behavior. “The closest I can describe it is to say they were touching light because they don’t see the light,” he says. “They process this invisible light as a new form of touch. So they change the way they move their heads. They scan the environment with sweeps of the head looking for light and this is not a typical way that animals perceive light. They created an exploratory behavior as a consequence of being able to perceive a new signal.”
Future experiments will also assess the possibility of fully developed infrared vision—equipping the brain with the equivalent of night vision goggles that can detect all of the contrast and intensity of the infrared environment. On the to-do list as well are devices that enable the perception of other forms of energy alone or in VISOR-like combination—X rays, magnetic fields or radio waves. “It’s pretty interesting to try to understand whether there’s a limit, whether the brain is really capable of adapting to combine a huge number of [electromagnetic] energies and altering our perception of world,” Nicolelis says.
A "sixth sense" prosthetic is in line with other research from Nicolelis's laboratory that is looking at technologies that will not only correct cognitive defects, but also extend and elaborate on the brain's organic capabilities—the ability to mix sensory perceptions between two rat brains is one possibility (shades of the Vulcan mind meld!). There are also plans for a brain-controlled exoskeleton to allow a handicapped child make the first kick for the 2014 World Cup.
The sixth-sense device might be one small step toward developing and implementing the science of Star Trek. It still may be a while, though, before Nicolelis's extra-sense machine will let a rat shift between parallel universes, as the VISOR did for Lt. Worf in "Parallels," the 163rd episode of Star Trek: The Next Generation.