By using a mental map oriented to the north, says a group of psychologists
To navigate certain parts of New York City — namely Queens and much of Manhattan — all you need to be able to do is count. In Manhattan neighborhoods like the West Village, and most of Brooklyn, things get a good bit trickier. You can no longer depend on the logical numbered progression of streets and avenues, and must instead rely on some other picture inside your head.
For a while now psychologists have debated just what that picture looks like. Some believe we need to orient ourselves by local reference points. Under this theory, we're lost until we see that certain street or certain landmark, at which point the rest of the grid emerges in our minds. Others argue that experience is our mental cartographer. This idea suggests that if you cruise around the city enough, you develop a spatial memory that helps you find your way no matter which direction you face; at the same time, if this is true, it should become harder to reach a destination that's farther from your familiar starting point.
A third alternative suggests that our internal GPS system is informed by frequently looking at maps. In other words, the more time we spend finding directions on Google Maps, the more our minds may grow familiar with the officially documented outline of our city, rather than the one created through our own experiences. This idea receives support in a recent study published online late last month, ahead of print, in the journal Psychological Science. A team of psychologists led by Julia Frankenstein of the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, found evidence that we're best oriented when facing north — just like a reliance on maps would suggest.
Frankenstein and colleagues recruited 26 people from Tübingen to participate in a test of spatial knowledge of their home. Wearing helmets that produced a virtual model of the city, the participants were placed in five initial locations. They saw each location from a total of 12 perspectives — each shifted 30 degrees from the one before. At each of these views the participants had to point toward a familiar target in the city: a train station, a museum, major intersections, and even well-known taverns. The researchers recorded how long it took people to get situated in their starting point, and also how accurately they pointed to various sites.
Their results suggest that our mental maps rely less on local reference points or memory-based maps and more on geographical orientation. Alignment with a well-known street didn't improve pointing performance, as the local theory would suggest. And a person's distance from the target site didn't have as great an impact on pointing accuracy as the memory theory would suggest. Instead the angle of the initial location best predicted a person's pointing accuracy, and pointing errors were clearly lowest when people faced north:
"Our results support the popular belief that people have access to something like a map in their heads and suggest that—at least for our participants from Tübingen—this map is oriented north," Frankenstein and colleagues conclude. Still they found the result a bit "surprising."
For one thing, the landmarks they chose aren't on typical maps, and some of the participants reported not having viewed a map of Tübingen for decades. So even though people had spent much more time navigating the city by memory than by map, their mental views of the city still seem drawn in a map style. It's almost as if people use their experience to situate themselves in a city, then consult the north-pointing map of that same city in their minds to find their way, the authors conclude:
Participants therefore had to identify their location and orientation using knowledge they had gained from navigating the city and then relate this navigational knowledge to map knowledge, thereby switching from a ground perspective to a bird’s-eye view.