People who grew up in rural areas have better sense of direction than those raised in cities, particularly cities with grid-pattern streets, a new study says. Researchers say it may be because the countryside has more disorderly road layouts, which effectively primes the brain for remembering and navigating environments. The scientists from France and London tested nearly 400,000 people from 38 countries on their spatial navigation, using a video game called Sea Hero Quest. The mobile game, designed to help research into dementia, involves directing a virtual boat around certain routes that players have had to memorise. The authors found that individuals who grew up in more structured, grid-like cities, such as Chicago, performed better on game levels with a similar grid-like layout.

Video games are one of the most misunderstood forms of entertainment. In one sense, it's easy to see why: if you haven't had much interaction with them, watching someone play one can be a pretty unsettling experience. Gamers can often give the impression that they're glued to the screen, absorbed in what feels like the digital equivalent of junk food. At best, it seems like a pointless thing to do; at worst, we worry that games are socially isolating, or actively harmful. One of the longest-standing tropes about video games is that violent ones – like Call of Duty or Fortnite – can cause players to become more aggressive in the real world.

The world's largest dementia research experiment, which takes the form of a video game, has indicated the ability to navigate declines throughout life. The findings, presented at the Neuroscience 2016 conference, harnessed data from 2.4 million people who downloaded the game. Getting lost is one of the first symptoms of Alzheimer's disease. And the researchers at University College London believe the results could help make a dementia test. Sea Hero Quest is a nautical adventure to save an old sailor's lost memories.

A mobile phone game that tests spatial navigation skills and has been played by 2.4 million people, has become the largest dementia study in history and raised hopes of a breakthrough in diagnosing the disease. Sea Hero Quest, a collaboration between Alzheimer's Research UK, Deutsche Telekom, game designers Glitchers and scientists, has generated the equivalent of 9,400 years of lab-based research since its launch in May. Experts hope to use the data to create the world's first global benchmark for spatial navigation, one of the first abilities affected by dementia, and to develop the game into an early diagnostic test for the disease, which is the leading cause of death in England and Wales. Dr Hugo Spiers, of University College London, who presented the preliminary findings at the Neuroscience 2016 conference in San Diego, said: "This is the only study of its kind, on this scale, to date. Its accuracy greatly exceeds that of all previous research in this area.

If there's one thing that I've learned in the few short years that I've been a fully-fledged scientist, it's that time is one of the most valuable commodities that you can give a researcher. In all its myriad forms, time is invaluable to the scientific process – time to develop ideas, time to write grants. The time that you need to run an experiment. Critically, the time that participants are willing to give you in the pursuit of knowledge. It's a precious thing, for everyone involved.