Multisensory Perception and Action Group, Max Planck Institute for Biological Cybernetics, Spemannstrasse 41, 72076 Tübingen, Germany.
Curr Biol. 2009 Sep 29;19(18):1538-42. doi: 10.1016/j.cub.2009.07.053. Epub 2009 Aug 20.
Common belief has it that people who get lost in unfamiliar terrain often end up walking in circles. Although uncorroborated by empirical data, this belief has widely permeated popular culture. Here, we 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. We 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 (diameter < 20 m), though rarely in a systematic direction. These results rule out a general explanation in terms of biomechanical asymmetries or other general biases [1-6]. Instead, they 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.
人们普遍认为，在陌生的地形中迷路的人往往会最终走成圆圈。尽管这种观点没有得到经验数据的证实，但它已广泛渗透到流行文化中。在这里，我们在两种不同的环境中测试了人类在陌生地形上沿直线行走的能力：一个是大型森林区，另一个是撒哈拉沙漠。通过全球定位系统捕捉了数小时的行走轨迹，结果表明，当参与者看不到太阳时，他们会反复走成圆圈。相反，当太阳可见时，参与者有时会偏离直线，但不会走成圆圈。我们通过评估参与者在蒙住眼睛的情况下保持固定路线的能力，测试了这种行走行为的各种解释。在这些条件下，参与者经常走成小圆圈（直径 < 20 米），尽管很少是系统的方向。这些结果排除了一般的解释，即生物力学不对称或其他一般偏差[1-6]。相反，它们表明偏离直线是传感器运动系统中积累噪声的结果，如果没有外部方向参考来重新校准主观的直线前进，可能会导致人们走成圆圈。
