Photo via flickr by gavinrobinson
Common belief has it that people who get lost in unfamiliar terrain often end up walking in circles. New research in the journal Current Biology suggests that, in fact, people do tend to walk in circles if they do not have a reference point such as the sun.
Researchers at the Max Planck Institute for Biological Cybernetics in Germany recently tested the ability of humans to walk on a straight course through unfamiliar terrain in two different environments: a large forest area and the Sahara desert. Walking trajectories of several hours were captured via global positioning system, showing that participants repeatedly walked in circles when they could not see the sun. Conversely, when the sun was visible, participants sometimes veered from a straight course but did not walk in circles.
“Walking in a straight line is a complicated process when you think about it from the perspective of the brain,” said Jan Souman, researcher at the Max Planck Institute for Biological Cybernetics.
Their hypothesis is that the longer people walk, their errors in relation to a straight line build up by chance to the left or right. This may result in a zigzag pattern. Over time, the tendencies to the left or right may take the person in a circle.
The researchers tested various explanations for this walking behavior by assessing the ability of people to maintain a fixed course while blindfolded. Under these conditions, participants walked in often surprisingly small circles, though rarely in a systematic direction. These results suggest that veering from a straight course is the result of accumulating noise in the sensorimotor system, which, without an external directional reference to recalibrate the subjective straight ahead, may cause people to walk in circles.