Holy Bat Sight!

Posted on July 15, 2013

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If you can hear you have no difficulty locating an echo, a favorite activity of hiking kids everywhere. But if you can’t see, an echo can help your brain envision your surroundings. Some talented visually impaired individuals adapted a bat-like ability to use echoes to “see.” By using a series of tongue clicks they “bounce” sound off objects in their surroundings and “listen time” the faint returning echoes. (No, these individuals are not X-Men, they are everyday people like you and me.)

They click their tongues, and the amount of time the sound takes to bounce off the objects and return to the person’s ear enables the superlistener to gauge the object’s distance, size, and even shape. Echolocation, as this is called, can be so accurate that some blind echolocators can ride bikes, navigate cities, or even play basketball without any assistance. One teen who lost his eyes to cancer wins at foosball, rollerblades on city streets, and hit his siblings with a pillow from across the room.

All that may sound bat-shite crazy, but it’s really bat sight. Crazy! You see, echolocation is the same method a bat uses to find and track mosquitoes in the dark, and now research tells us this ability actually lies dormant in humans. We used to think this ability was exclusive to the likes of bats and dolphins, and maybe Aquaman. But new research from Canada compared brain activity in sighted and blind echolocation experts. The comparison showed only the brains of blind echolocators had developed a way to interpret these echoes into a kind of sonic sight. To them, echolocation–while using sound–is a form of visual navigation. Researchers were surprised that in the absence of sight the visual cortex continues to be in charge of organizing and categorizing our world like a Richard Scarry book. Even when the only information given is sound.

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Athough it’s the visual cortex of the blind brain that “lights up,” or responds during a functional MRI (fMRI) once the echoes are perceived, this is not to say the echolocators are seeing an image light up in their mind’s eye like a Lite-Brite. It’s actually more like they are mapping a 3-D impression of the object in the surrounding space. That is what gives the echolocator their bearings, helps them navigate, and allows them to “see” what may be coming at them. As far as the brain is concerned, it’s like biological sonar, which could come in handy when the GPS loses satellite information on your next hike… or when you’re looking for mosquitoes on your next hiking trip.

Kiped from the archives of the SyFy channel’s IdeaLab Blog for the TV show Eureka. Well kinda kiped, since I wrote it to begin with. Edited by Tiffany Lee Brown, without whom I’d be stuck in the land of curly quotes.

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Posted in: science, writing