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Are Google Maps and GPS bad for our brains?

( Illustration by Ben Kirchner)

A famous study of London taxi drivers, conducted in the late 1990s, found that an area of the cabbies' hippocampi was much larger than normal. The hippocampus is thought to be the place where we store maps of our surroundings. It plays a crucial role in our ability to keep track of where we are and to get from one place to another. As the taxi drivers built their mental maps of London's incredibly complex road network, the study indicated, their hippocampi expanded, and their navigational skills strengthened.

Eleanor Maguire, the neuroscientist who led the study, fears that if the cabbies adopt satellite navigation, their hippocampi will shrink, and they'll lose much of their remarkable navigational sense. "We very much hope they don't start using it," she told a reporter for Britain's Independent newspaper.

All of us who rely heavily on computer maps and GPS devices are exercising our innate navigational skills less frequently and less intensively. As a result, those skills are probably decaying. And if our kids rely on computer maps from a young age, they may never establish those skills in the first place. When we upgraded from atlases to gizmos, we made our lives easier. But we lost something, too.

Just like the cabbies, we may be fated to experience a dwindling in the size and functionality of the part of the hippocampus devoted to representing space. As that happens, we'll begin to lose touch with the physical world that surrounds us. And in turn, we'll become even more dependent on our computers to shepherd us around. We'll turn into modern-day Hansels and Gretels, lost without our digital trail of crumbs.

But here's the really scary part. In addition to stockpiling mental maps, the hippocampus plays an essential role in creating and storing memories. Some studies have found, in fact, that a shrinking hippocampus is a risk factor for Alzheimer's disease.

VĂ©ronique Bohbot, a professor of psychiatry at McGill University in Montreal, has done extensive research demonstrating the connection between the size of the hippocampus and the degree to which we employ our navigational skills. She worries that, should our hippocampi begin to atrophy from a lack of use in navigation, the result could be a loss of memory and a growing long-term risk of dementia.

"Society is geared in many ways toward shrinking the hippocampus," she said in an interview with journalist Alex Hutchinson last year. "In the next twenty years, I think we're going to see dementia occurring earlier and earlier."

That's still speculation. Bohbot's fear may well turn out to be groundless. But it's something to keep in mind the next time that pleasant, computer-generated voice tells you to take a left.

Nicholas Carr is the author of the new book "The Shallows: What the Internet Is Doing to Our Brains."

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