Citing multiple navigational studies, a correspondent for Nature says navigation is a use-it-or-lose-it skill.

Put simply: When our eyes and ears are trained on our smartphones, they're not aware of the outside world, and we start to lose our ability to navigate.

On the other hand, when we do train our navigational skills, the human brain physically responds. In one study, the memory-retaining portion of the brain — the hippocampus — literally grew in size after taxi drivers committed routes to memory.

So what's the takeaway? It's really quite simple: A spatial cognition psychologist at Tufts University suggests you pay attention to your environment.

GPS is handy, but there are cognitive downsides to relying solely on technology-based navigation.