Abstract

Biological odometry refers to the capacity for perceptually measuring distances traveled during locomotion. In the case of haptic odometry, information about distance traversed is generated from the movements of the legs, with coordinated leg motions (i.e., gait patterns) producing patterns of tissue deformation detectable by the haptic perceptual system. The gait symmetry theory of haptic odometry classifies gaits based upon the symmetry of muscle activation patterns. This classification identifies candidate higher-order variables of haptic odometry and provides a promising basis for understanding the associated patterns of tissue deformation detected by the haptic perceptual system. The theory successfully predicts biases (i.e., underestimations/overestimations) resulting from the manipulation of the gait patterns used in the outbound and return phases of homing tasks. We test gait symmetry theory by considering a previously unexamined key prediction. Two-legged hopping and walking have the same symmetry group classification, therefore, a homing task completed using any combination of two-legged hopping and walking as the outbound/return gaits should produce no systematic biases. Contrary to this prediction we observed systematic biases. We discuss the possibilities for modifying gait symmetry theory to account for our findings, and we present a new alternative theory based upon spatial reference frames.

摘要

生物测距法是指感知地测量运动期间行进距离的能力。在触觉测距法的情况下，从腿部的运动生成有关经过的距离的信息，协调的腿部运动（即步态模式）产生可由触觉感知系统检测到的组织变形模式。触觉测距法的步态对称理论基于肌肉激活模式的对称性对步态进行分类。该分类标识了触觉里程表的候选高阶变量，并为理解由触觉感知系统检测到的组织变形的相关模式提供了有希望的基础。该理论成功地预测了偏差（即，低估/高估）是由于在归巢任务的出站和返回阶段使用步态模式而产生的。我们通过考虑先前未经检查的关键预测来测试步态对称性理论。两足跳跃和步行具有相同的对称组分类，因此，使用两足跳跃和步行的任意组合完成的归巢任务作为出站/返回步态应该不会产生系统性偏差。与这一预测相反，我们观察到系统的偏差。我们讨论了修改步态对称性理论以解决我们的发现的可能性，并提出了一种基于空间参考系的新替代理论。两足跳跃和步行具有相同的对称组分类，因此，使用两足跳跃和步行的任意组合完成的归巢任务作为出站/返回步态应该不会产生系统性偏差。与这一预测相反，我们观察到系统的偏差。我们讨论了修改步态对称性理论以解决我们的发现的可能性，并提出了一种基于空间参考系的新替代理论。两足跳跃和步行具有相同的对称组分类，因此，使用两足跳跃和步行的任意组合完成的归巢任务作为出站/返回步态应该不会产生系统性偏差。与这一预测相反，我们观察到系统的偏差。我们讨论了修改步态对称性理论以解决我们的发现的可能性，并提出了一种基于空间参考系的新替代理论。