Using a satnav ‘switches off’ parts of the brain that would normally be used to simulate different routes, according to research by University College London (UCL).
A study, published in Nature Communications and funded by Wellcome, involved 24 volunteers navigating a simulation of Soho in central London while undergoing brain scans.
The researchers studied activity in the ‘hippocampus’, a brain region involved in memory and navigation, and the prefrontal cortex which is involved in planning and decision-making. They also mapped the labyrinth of London’s streets to understand how these brain regions reacted to them.
When volunteers navigated manually, their hippocampus and prefrontal cortex had spikes of activity when volunteers entered new streets. This brain activity was greater when the number of options to choose from increased, but no additional activity was detected when people followed satnav instructions.
“Entering a junction such as Seven Dials in London, where seven streets meet, would enhance activity in the hippocampus, whereas a dead-end would drive down its activity. 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,” explained senior author Dr Hugo Spiers (UCL Experimental Psychology).
“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.”
According to UCL, the study suggests that drivers who follow satnav directions do not engage their hippocampus, potentially limiting any learning of the city street network.