Spikes of Activity in Two Key Areas of the Brain
The UCL team wanted to see the effects on the brain of navigating with and without a GPS. For their study, they recruited 24 men and women aged between 20 and 35, with good eyesight, sense of direction, no history of neurological disease and minimal knowledge of London's streets. The test area chosen was Soho. This is a dense network of streets, shops, restaurants and bars in central London. A week before the test, the participants were given maps to familiarize themselves with the layout of the area. The maps included every street name, place of interest and end-of-journey location. The day beforehand, they were given a two-hour walking tour of Soho. When it came to the test they were asked to "drive" a computer-simulated vehicle through the area's narrow streets while their brains were being scanned. The researchers found that when the volunteers were manually navigating their way around the district, there were spikes of activity in the hippocampus. This part of the brain is involved with navigation, learning, and spacial memory; it helps retrieve the past to simulate the future. There were also spikes of activity in the prefrontal cortex, which is concerned with planning and decision making. But there were no spikes when the drivers relied on the GPS device. Activity remained at normal levels, suggesting that these areas of the brain are not engaged when a person is relying on instructions. This limits the ability to learn the street network. This doesn’t surprise me. You don’t really "learn your way around" when you’re using GPS. You’re not oriented to where you are in space. You’re just turning left or turning right or changing lanes as you’re told.London's Cab Drivers Have Bigger Brains
The results supported a previous UCL study where the researchers found that drivers of black taxis have a larger hippocampus. To be awarded a license to drive a black cab, students have to spend three to four years mastering "The Knowledge" - 320 routes, 25,000 streets and 20,000 landmarks and places of interest in central London. A larger hippocampus allows them to store a detailed mental map of the city. The brain actually changes its structure to accommodate an excessive amount of navigation info. Lead researcher of the current study Dr. Hugo Spiers said, "If you are having a hard time navigating the mass of streets in a city, you are likely putting high demands on your hippocampus and prefrontal cortex. "Our results fit with models in which the hippocampus simulates journeys on future possible paths while the prefrontal cortex helps us to plan which ones will get us to our destination. "When we have technology telling us which way to go, however, these parts of the brain simply don't respond to the street network. In that sense our brain has switched off its interest in the streets around us." Commenting on the study, Dr. Dean Burnett, a neuroscientist at Cardiff University, said, "If you want to become better at spatial navigation, then you should avoid satnavs where possible." Readers of this newsletter know that you can build brain and memory capacity by making your brain do some work – learn a musical instrument, learn a second language, learn a craft like knitting. All of these fend of the day when your brain loses the ability to do the things you want. Turning off the GPS and reading a map is in that category. It may be a small thing, but it’s a chance to give your brain a needed workout.