Echolocation: Bats, Dolphins, and Ben Underwood, Who Is Blind

Echolocation: Bats, Dolphins, and Ben Underwood, Who Is Blind

"To society he's blind," said Ben's mother, "but that doesn't make him handicapped. He just can't see."

One morning when he was 2, Ben woke up and told his mother, "Mom, I can't see anymore, I can't see anymore." His mother knew he had an incurable retinal cancer, and put his hands on her face. She replied, "Baby, yes, you can see. . . . You can see with your hands." She told him that he could see with his hands and his nose and his ears. She had three other children and could not afford to treat his blindness as a handicap.

So Ben grew up without sight, but at age five learned to click with his tongue about every half second—to echolocate—to ride his bike, shoot hoops, play video games, and throw pillows at his sisters.

Done for popular consumption, most media accounts of Ben are hyped and do not address deeper questions about the brain's ability. Neuroscientists no longer believe the occipital cortex is useless in the blind; rather, it can activate through learned echolocation. It creates images with or without eyes.

Bats send sound signals in rapid bursts at high frequencies. Their sonar can bounce off flying mosquitoes, which the bats swoop on with open mouths. Dolphins find their meals in the same manner. It is called echolocation, using sound to identify objects and their locations. As with vision, the brain processes energy reflected off an object—only as sound rather than light. Echoes can inform Ben as to the position of objects, how big they are, their general shape, and how solid they are. Positioning determines distance and whether it is left or right, high or low, front or back. In shape, Ben tells if it is tall or short and wide or narrow. Ben may recognize a pole because it is tall and narrow. A building is tall and very broad. A pillow is soft and not dense.

By clicking, Ben avoids curbs while riding his bicycle in his Sacramento, California neighborhood. Even though he can't see the hoop, he can sink a basketball through the basket. He plays video games by distinguishing sounds. He is writing a novel, typing it at 60 words per minute on a standard keyboard. He roller blades, plays foosball and skate boards. His eyes are artificial, so they see nothing. "I can hear that wall behind you over there. I can hear right there -- the radio, and the fan," Ben told one reporter.

Ben is not the only blind person who has developed echolocation. Others are Daniel Kish, 40, of Long Beach, California, who leads other bind people on hikes in the wilderness or in mountain biking. "I have mental images that are very rich, very complex,” says Kish. He can describe the awesome beauty of a wilderness scene. James Holman (1786-1857) used the sound of a tapping cane to travel around the world.

In an earlier post, I did a piece on Graham Young, a man who is blind but somehow can see. Young can sense moving objects but doesn't know how he does it. V.S. Ramachandran, a neuroscientist, has a plausible explanation for Young's ability.

Though we have explanations for Ben's ability, not nearly enough research has been done on this phenomenon and, despite remarkable progress, the brain itself remains a largely unexplored frontier, an unknown continent. We look out into space and imagine black holes and time warps, but an entire universe also lies in the other direction.

I am left with mystery.  Sadly, this amazing boy died of another cancer after the one that took his eyes.