My husband on a trek without GPS.
Over three millennia ago, the people of Oceania, illiterate and unable to perform numerical calculations, were able to successfully navigate thousands of kilometers across the Pacific. Their genius was in their keen power of observation.
Today, it’s hard to imagine sailors traversing such vast stretches of ocean without maps or instruments. These Polynesian navigators crafted an intricate navigation system based on natural elements. They used the stars, sun, ocean waves, wind patterns, and even the bioluminescence of marine organisms as their guide. Stories and songs served as memory aids for this knowledge. They navigated by the stars to a point upwind of their destination, and then used observations of the ocean, wildlife, and cloud formations to sail downwind to their endpoint.
Other ancient cultures from more temperate regions, like the Egyptians, Mesopotamians, Greeks, and Vikings, also navigated by relying on the stars.
By the 18th century, technological innovations like the marine chronometer and sextant were used to measure latitude and longitude with greater precision. Yet even with these tools, sailors still relied heavily on observing the sea and watching the horizon. It wasn't until the last century, with the invention of radar and satellite navigation systems, that humans began to keep their eyes more on instruments than on their environment.
Some of you might remember using paper maps (and the hassle of folding them back up). With them, people still had to compare the terrain with the map, using observation and interpretation. Then came Google maps, which fundamentally transformed how we navigate by listing directions like a recipe, step-by-step, breaking down a route into digestible bits of space.
And now we have GPS. The first GPS satellite was launched in 1989, and after the smartphone’s introduction in 2007, GPS became ubiquitous. With GPS, we no longer use our spatial navigation capabilities; we follow instructions. For the Polynesians, their observation system was the pinnacle of human ingenuity, for us now, it is GPS.
When humans navigate, they can rely on one of two distinct strategies: one is an internal, cognitive map, a deeply ingrained sense of place, forged through evolution, constantly updated by our observations of the world around us. Or, we can use a rote step-by-step system of instructions, like with GPS, following commands from a customizable voice, in a stimulus-response pattern (“at the corner turn right, in 500 feet turn left”). When we use GPS, we surrender something essential: the ability to observe, to comprehend, and to pay attention to our surroundings.
A study published in Nature backs up the claim that we’ve lost something. Fifty people who regularly relied on GPS were brought into a lab to perform a navigation task. The results were clear: the more people used GPS in their daily lives, the less they used spatial memory for the task, and the more they defaulted to a stimulus-response strategy--like following a recipe. They struggled to form cognitive maps and paid attention less to landmarks to guide them. The bottom line? Greater use of GPS was correlated with a decline of spatial memory ability. The authors suggest that with more GPS use, people rely less on their hippocampus, that ancient structure deep within the brain involved in spatial memory.
Indeed, a study found that the hippocampus is actually smaller among people who use their spatial memory less. London taxi drivers, renowned for their exceptional navigation skills, are a prime example of how spatial memory can develop. To earn a taxi license, it takes them two years to master the intricate layout of the city, what they call “The Knowledge.”
London taxi drivers were ideal subjects to study how spatial navigation affects the brain. Researchers at University College London (UCL) used MRI (magnetic resonance imaging) scans to compare the brains of taxi drivers with those of non-taxi drivers. The study was done in 2000, before smartphones and GPS navigation systems became mainstream (both happened in 2007).
The results were striking. The taxi drivers had a significantly larger volume of gray matter in the posterior hippocampus—the very region responsible for spatial navigation. And the longer they drove, the more pronounced was this increase.
This study highlighted the brain’s remarkable plasticity—its ability to adapt and reorganize based on the environment and experiences. Navigating a city without relying on GPS and using an internal cognitive map reshapes the brain itself.
London bus drivers also know the city well, but they drive through fixed and repetitive routes. Another study found that the bus drivers had less gray matter in the posterior hippocampi compared to the taxi drivers. This suggests that it’s not any type of driving, but rather winding through diverse, unpredictable routes that enhances the volume of the posterior hippocampus.
In our modern digital era, we tend to have a limited range of activity. A study I did with colleagues tracked 750 information workers for a year with sensors. We found they spent 90% of their time sedentary in their offices—a habit that isn't healthy. It turns out that a greater diversity of daily activity is associated with a larger hippocampus volume.
The hippocampus is one of the first parts of the brain to deteriorate in Alzheimer's disease, with sufferers often losing their ability to navigate. A global study of millions of people done by UCL tested their spatial navigation ability using a virtual reality game. The goal is to develop a task for early detection of Alzheimer’s. Among their findings, they found that people who grew up in rural or rural/urban environments had better spatial navigation ability than those who grew up in cities, particularly in those with a regular grid-like layout.
In today’s world, GPS offers undeniable convenience, too many benefits to give it up at this point. With our fast-paced lives and tight schedules we rely on GPS to optimize our minutes, to avoid gridlock, and of course to help us find our way. Clearly it has made our lives easier.
And yet, though GPS has extended our capabilities it has also lessened them in other ways. The truth is, relying on our internal maps and not the screen sharpens us. It teaches us the landscape, the details that stick and make a place ours. It makes us agile. You notice things, maybe a path you didn’t see before, an interesting cafe, or a glimpse of autumn’s brilliance in a line of trees. When I use my GPS in New York City, it finds me the fastest route, for sure. But something’s also lost. I no longer pay attention to my surroundings and savor what’s along the way.
Next time you find yourself in an unfamiliar place, resist the urge to pull out your phone. Be adventurous: take in the scenery, observe the landmarks, and form a map in your head. You can always fall back on GPS, but try it without, and you might discover a hidden corner of the world you would have missed by not being locked into the grip of your phone.
Perhaps GPS technology could evolve to support our spatial abilities instead of weakening them. I’ve noticed that sometimes it will mention a landmark, e.g. “turn right at the Citibank building”. What if GPS systems integrated more ways to engage us with our environment, such as suggesting a spot to watch migratory birds? One proposal uses 3D spatialized audio to guide people to a destination.
Navigating is a fundamental human property. The hippocampus has evolved to help us find our way. Yet in our modern digital age we’re letting it wither, like an unused muscle that atrophies.
In a world of satellites and smartphones, we’re not just changing how we get from place to place; we are changing the very wiring and structure of our brains. The cost of convenience, it seems, is being paid in the currency of gray matter, as we disengage more and more from the environment around us.
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You can read more about how modern technology is changing our minds and behaviors in my book Attention Span.