Yardley L, Higgins M
Department of Psychology, University College London, United Kingdom.
J Vestib Res. 1998 Nov-Dec;8(6):435-42.
The remarkable accuracy with which healthy subjects can monitor their orientation while walking in darkness has been attributed to a process whereby awareness of orientation is automatically updated by information derived from active locomotion. The aim of this study was, first, to determine the contribution of vestibular information to the perception of orientation without vision, by comparing the accuracy of judgments of orientation following passive (seated) rotation about an earth-vertical axis with those following active (locomotor) rotation. The second aim was to assess whether monitoring orientation is indeed automatic, or whether it requires some degree of mental effort. This was evaluated by assessing whether accuracy in monitoring multiple passive or active rotations was affected by asking subjects to perform a mental task (that is, counting backwards) during rotation. The results indicated that although reliance on the primarily vestibular information available during passive rotation enabled subjects to accurately monitor single turns of up to 180 degrees, subjects were able to judge orientation after multiple turns more accurately after active rotation than after passive rotation, owing to the additional sensorimotor feedback gained from active locomotion. Accuracy in judging orientation was substantially impaired by backwards counting during both passive and active locomotion. This finding confirms that monitoring orientation during multiple turns in darkness necessitates central processing and adds to the growing body of evidence for the influence of mental activity on the perception and control of orientation.
健康受试者在黑暗中行走时能够显著精确地监测自身方向，这归因于一个过程，即方向意识会通过主动运动所产生的信息自动更新。本研究的目的，首先是通过比较绕地球垂直轴进行被动（坐姿）旋转后与主动（运动）旋转后方向判断的准确性，来确定前庭信息对无视觉情况下方向感知的贡献。第二个目的是评估监测方向是否确实是自动的，或者它是否需要一定程度的脑力劳动。这是通过评估在旋转过程中要求受试者执行一项脑力任务（即倒数）时，监测多次被动或主动旋转的准确性是否受到影响来进行评估的。结果表明，尽管依赖被动旋转过程中主要可用的前庭信息能使受试者准确监测高达180度的单次旋转，但由于主动运动获得了额外的感觉运动反馈，受试者在主动旋转后比被动旋转后能更准确地判断多次旋转后的方向。在被动和主动运动过程中，倒数都会严重损害方向判断的准确性。这一发现证实，在黑暗中多次旋转时监测方向需要中枢处理，并为心理活动对方向感知和控制的影响这一越来越多的证据增添了内容。
