The study, conducted by the University of Carnegie-Mellon, looked at 28 adults who played a driving video game. Half of the group, the control group, was asked to maneuver along 20 different routes for 45 minutes. The other group practiced maneuvering along a single route 20 times for 45 minutes.
Details of the study
The control group, by practicing 20 routes, was not able to practice enough to learn the details of all 20 routes in the time period. By contrast, the test group was able to maneuver along that route far faster. They were also able to do a better job drawing a two-dimensional picture of the route and were faster ordering a series of screenshots taken of that route. Now, this may seem incredibly obvious. If you practice driving alongside a single route, you will certainly get better at driving that route compared to someone who only practices that route one time out of 20. But the important part was that before and after the testing session, each participant underwent a brain scan using diffusion-weighted imagining (DWI), which measures water molecule activity in the brain.
Results of the brain scan
The brain scan found that those who practiced the one route repeatedly showed changes in the left posterior dentate gyrus. This area of the brain is part of the hippocampus, a region which controls memory and navigational ability. The hippocampus is a crucial region in understanding Alzheimer’s disease, as it is one of the first parts of the brain to be afflicted. And these changes did not just stay in the hippocampus. The Carnegie researchers noticed that there were increases “in the synchronization of activity – or functional connectivity – between this region and other cortical areas in the network of brain regions responsible for spatial cognition.” Furthermore, this structural change could be correlated with how well the test group people performed at navigating the route.
Implications for the rest of the brain
It had been known for years that taxi drivers, who have to navigate endless streets, have a larger hippocampus compared to others. But this study, appears to show that they develop this through their driving. This has important implications beyond navigation. For example, the hippocampus also affects one’s memory. A recent study by Columbia University which analyzed the hippocampus in rats shows that their brain cells – and by implication, ours – are capable of tracking time and distance. That is important due to the fact that we organize our memories through time, and that we link our sense of time with our sense of physical places. Scientists have understood that navigation and memory are linked in our brains for a long time. Hence, if it is possible to enhance one’s navigational ability, then perhaps this strategy could be used to improve one’s memory at the same time.
Plenty of work to be done
The Carnegie-Mellon researcher are understandably elated with what they have accomplished. As Marcel Just, the director of the Center for Cognitive Brain Imaging at the University observed, “We’re excited that these results show what re-wiring as a result of learning might refer to. We now know, at least for this type of spatial learning, which area changes its structure and how it changes its communication with the rest of the brain.” But there remains a great deal of work to be done to see how this link between spatial learning, an enlarged hippocampus, and memory can be used. Still, perhaps taxi drivers can take some pride in knowing that their constant navigating has other positive health effects. Featured photo credit: Kaysha via flickr.com
