Plight of the Navigators: Trusting our internal GPS

The Pearson Adventure collection is designed for intrepid riders, those who like to rely a bit less on their GPS and a bit more on what they see around them. And history shows we cyclists shouldn’t always depend upon others for guidance. People like Hieronymus Bosch, for example, whose Garden of Earthly Delights, painted in the 15th century, depicts a flat Earth floating in a sphere. Thankfully, the Ancient Greeks believed in a round Earth as early as the 5th century BC; it was Aristotle who pointed out the stars in Egypt were different to those in Cyprus, and thus concluded the Earth’s surface must curve.

By the sixth century, Indian scholars were able to calculate the circumference of this round Earth, to a distance of 39,968km. (The actual figure, measured by GPS, is 40,075km.) In the Middle Ages, Islamic astronomers made calculations based on the distance of a given point from Mecca. By the 10th century, the principles of triangulation they developed allowed them to calculate distance with an accuracy not replicated in the west until the 1600s.

In Polynesia, early Pacific islanders sailed across thousands of miles of ocean using maps of the stars committed to memory, then cross-referenced with familiar landmarks, such as recurrent bioluminescence in the water. The first bit of tech, the GPS of its day, arrived in the 17th century, courtesy of England’s John Harrison. A self-taught clockmaker, Harrison’s marine chronometers, or ‘sea clocks’, solved the previously intractable problem of calculating longitude at sea.

Eventually, came space satellites; by the late 1970s, NASA, in collaboration with the US Air Force, was testing numerous prototypes for a global positioning system. One, the brainchild of USAF officer Brad Parkinson, proved particularly effective and became the worldwide GPS we use today. (Parkinson originally developed his system to enable more accurate bombing of enemy targets.)

The idea that GPS might dull your mental acuity has been around for as long as the technology has been in mainstream use. Take the US driver, whose GPS took her into a Washington lake, whereupon she kept going in the belief it was a large puddle; or the Swedish couple who set out for Capri, in southern Italy, only to find themselves in Carpi, in the country’s north.

But it’s only recently that scientists have begun to fully understand what happens to the brain when we navigate using GPS. According to one headline-making study, in 2016, researchers at University College London found a key part of the human brain switches off when relying on external route-planning. Specifically, the hippocampus, the area of the brain which would otherwise calculate any number of different routes.

Scientists believe this might explain why, compared with the rest of the population, London taxi drivers exhibit noticeably enlarged hippocampi. The famous ‘Knowledge’ test requires London cabbies to memorise the capital’s streets in extreme detail; the city’s bus drivers on the other hand, who follow predetermined routes, do not display the same characteristics.

The bottom line seems to be use it or lose it, that an overreliance on GPS can cause the hippocampus to shrink; a theory that, in our age of digital spoon-feeding, can only be a good thing. We’re not saying GPS is all bad; it can offer helpful pointers when you’re puffing along a remote country road or battling up a climb. We simply suggest riders take a moment to look up, see where the treeline goes, or notice the direction of the wind. And if your cycling helmet starts to feel tight, that might just be your hippocampus, going for a ride of its own.