A Sixth Sense Could Help the Blind “See”

In a new study, blind rats could get around by directly incorporating geomagnetic information

M. Petosa/Photex/Corbis

While scientists are still working on strategies to give blind people back their vision, the authors of a new study have an alternative. They think they’re onto a “sixth sense” that, in some ways, could function similarly to sight. 

The researcher worked with blind rats to create an alternative "sense" that allowed the rats to navigate a maze. First, they connected a digital compass to electrodes, which, in turn, stimulated the rats’ visual cortexes. The composs fed geomagnetic information to the rats, and researchers found the rodents quickly learned how to incorporate that information. Soon, they could navigate through a maze as quickly as the rats with vision. 

New Scientist explains:

Whenever the rat positioned its head within 20 degrees either side of north, the electrodes sent pulses of electricity right into its right visual cortex. When the rat aligned its head in a southerly direction, the left visual cortex was stimulated. The stimulation allowed blind rats to build up a mental map of their surroundings without any visual clues.

Researcher Yuji Ikegaya, of the University of Tokyo, says the findings demonstrate how adaptable the mammalian brain is. He thinks their results could also have implications for people, too -- for example, geomagnetic sensors could be attached to the canes used by some blind people to get around to provide another source of sensory input.

But why stop at adding just one sense, when we could have so many more? “[T]he researchers expect, based on their findings, that humans could expand their sense through artificial  sensors that detect geomagnetic input, ultraviolet radiation, ultrasound waves, and more,” a press release said. “Our brains, it appears, are capable of much more than our limited sense allow.” Other scientists are pushing this idea, too—at the 2015 TED conference, neuroscientist David Edelman explored the idea of creating new sense for humans:

Some blind people are already well aware of the elastic capabilities of the human brain the ones who have trained themselves to “see” relatively clearly by clicking their tongues to produce echolocation

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