Using GPS navigation to get to your destination may 'switch off' parts of the brain that would otherwise be used to simulate different routes, a new study has found.
The study by researchers at University College London (UCL) in the UK involved 24 volunteers navigating a simulation in central London while undergoing brain scans.
They investigated 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.
"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," said Hugo Spiers from UCL.
"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 do not respond to the street network. In that sense our brain has switched off its interest in the streets around us," he said.
Previous research has shown that the hippocampi of London taxi drivers expand as they learn to memorise the streets and landmarks of central London.
The latest study suggests that drivers who follow satnav directions do not engage their hippocampus, likely limiting any learning of the city street network.
The study was published in the journal Nature Communications....