Dear Doctors: My wife and I have a running argument with our kids about GPS. We enjoy maps and use them to plan our routes. Our kids call us old-fashioned and always use GPS. I just read that can erode your spatial skills. Is that true? If so, maybe it will persuade them to use a map.
Dear Reader: There's no denying the ease of plugging an address into a GPS device and getting turn-by-turn guidance to your location. This typically includes an arrival time that gets updated based on your progress; alerts about accidents, road conditions and other delays; and offers of alternative routes as needed. But recent studies suggest that ceding the planning and execution of daily travel to global positioning systems can exact a cognitive price. That is, when GPS use becomes habitual, it's not just the skills associated with reading a map that get rusty. A growing body of research suggests that a specific area of the brain associated with navigation and spatial location may suffer as well.
Worries that new information-related technologies can harm the brain date back centuries. In the 1700s, novels soared in popularity. This raised alarms over their potential to damage mental acuity and mental health. The advent of broadcast radio at the start of the 20th century, soon followed by television, led to similar worries.
A study from Johns Hopkins University in Baltimore suggests worries about too much TV may have merit. Researchers tracked the viewing habits of 599 volunteers. After 11 years, those who had logged the most hours had the greatest reduction in volume of the entorhinal cortex. That's an area of the brain associated with memory, navigation and the perception of time.
And that brings us back to reliance on GPS. At issue is the hippocampus, an ancient structure located deep in the brain, behind the ear and near the base of the skull. It oversees spatial orientation and memory, is key to planning and decision-making and appears to play a role in our ability to imagine the future. A reduction in the size of the hippocampus is seen in Alzheimer's disease and other types of cognitive impairment. Aging, depression and chronic stress can also cause the hippocampus to atrophy. Now, recent research suggests that we stop exercising that important part of the brain when we rely on GPS.
A study in the journal Nature Communications found that people responding to spoken directions while driving had measurably less activity in the hippocampus than did those doing their own navigation. Researchers in Canada saw marked declines in spatial memory in chronic GPS users. Coming at the question from a different direction, neuroscientists in England found that the hippocampi of newly hired London cab drivers grew significantly larger year by year, as their knowledge of the city's streets increased.
The takeaway is that engaging in navigation can improve the health of your brain. In fact, neurologists recommend upping the ante by adding physical activity into the mix. Activities such as orienteering, a sport in which participants use a map and a compass to navigate unknown terrain, can help maintain, and even boost, brain plasticity.
(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
