Lost? You will walk in circles
Have you ever been lost and felt like you were walking around in circles? Well, you're not alone, and it's not just your imagination. An international team of scientists has presented the first empirical evidence that people really do walk in circles when they are in unfamiliar territory and have nothing to guide their way. The findings are published in the journal Current Biology. The Canadian, French and German researchers found that a lack of reliable cues to determine walking direction is what compels people to walk in circles. The team succeeded in cementing what researchers and the general public have long suspected. Drs Jan Souman and Marc Ernst from the Multisensory Perception and Action Group at the Max Planck Institute for Biological Cybernetics in Germany led the study that examined the walking trajectories of people who walked for a number of hours in the Bienwald forest area in Germany and in the Sahara desert in Tunisia. A global positioning system (GPS) was used to record their trajectories. Based on the results, the participants succeeded in maintaining a straight path when the sun or moon was visible. Everything changed when clouds blocked the sun or moon; the participants walked in circles without realising it. In Germany, six participants walked for many hours in a large, flat forest; four of these participants walked on a cloudy day with the sun hidden. The team found that these four walked in circles, and three of them failed to realise that they had crossed their own paths. The two remaining participants walked when the sun shone brightly and succeeded in walking a near-perfect straight course. In Tunisia, three other participants walked in the Sahara desert; two of them walked when the sun was out, while the third walked at night with a full moon. While the 'day' walkers veered slightly off course, they did not walk in circles. The 'night' walker made a number of sharp turns when the moon was blocked by clouds, bringing him back to his starting position. 'The stories about people who end up walking in circles when lost are actually true,' explained Dr Souman. 'People cannot walk in a straight line if they do not have absolute references, such as a tower or a mountain in the distance or the sun or moon, and often end up walking in circles.' The study demonstrates that the circular paths are seldom systematic. Dr Souman pointed out that the same person may choose to go left, then choose to go right, only to end up in the position they started from. 'One explanation offered in the past for walking in circles is that most people have one leg longer or stronger than the other, which would produce a systematic bias in one direction,' commented Dr Souman. 'To test this explanation, we instructed people to walk straight while blindfolded, thus removing the effects of vision. Most of the participants in the study walked in circles, sometimes in extremely small ones (diameter less than 20 metres).' For his part, Dr Ernst said: 'The results from these experiments show that even though people may be convinced that they are walking in a straight line, their perception is not always reliable. People need to use reliable cues for walking direction in their environment; for example, the position of the sun.' Drs Souman and Ernst plan to further investigate how people use these and other sources of information to guide their walking direction. Virtual reality equipment, such as an omnidirectional treadmill, will be used by participants to find their way through a virtual forest. The scientists believe this will allow them to have more control over the information given to the subjects, and will allow for better test explanations.
Countries
Canada, Germany, France