The research suggests navigation aids limit the brain's natural tendency to learn city street networks.

Neuroscience researchers have developed a better understanding of how GPS navigation guidance 'switches off' certain parts of the brain that would otherwise help figure out a route and memorize streets.

The University College London study analyzed brain scans from a few dozen volunteers navigating a simulation of urban street networks, such as the Soho district of central London. Real-time data was compared against specific map features, allowing researchers to determine how the brain reacts to certain types of intersections.

The study focused on data from the hippocampus, involved in memory and navigation, and the prefrontal cortex, which helps handle planning and decision making.

"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," says senior author Dr Hugo Spiers. "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."

The team developed a better understanding of the relationship between street complexity and brain activity. London's arbitrary maze of small streets meeting at different angles is particularly stimulating to the hippocampus, while "much less effort" is needed to navigate Manhattan's grid layout. The researchers suggest the findings could be beneficial beyond the obvious implications for city planning.

"For example, we could look at the layouts of care homes and hospitals to identify areas that might be particularly challenging for people with dementia and help to make them easier to navigate," Spiers adds. "Similarly, we could design new buildings that are dementia-friendly from the outset."