Tresilian James R, Wallis Guy M, Mattocks Craig
Perception & Motor Systems Laboratory, School of Human Movement Studies, University of Queensland, 4072, St Lucia, Australia.
Exp Brain Res. 2004 Nov;159(2):251-7. doi: 10.1007/s00221-004-1994-y. Epub 2004 Oct 2.
To understand performance of evasive and interceptive actions it is important to know how people decide when to initiate a movement-initiating at the 'right' moment is often essential for successful performance. It has been proposed that initiation is triggered when a perceptually derived quantity reaches an invariant criterion value. Candidate quantities include time-to-collision (TTC), distance, and rate of image expansion (ROE), all of which have received empirical support. We studied initiation of an evasive manoeuvre in a computer-simulated steering task in which the observer was required to steer through a stationary visual environment and avoid colliding with an obstacle in their path. The results could not be explained by hypotheses which propose that evasive manoeuvre initiation is based on a fixed criterion value of TTC or distance. The overall pattern was, however, consistent with the use of a criterion ROE value. This was further tested by analyses designed to directly evaluate whether the ROE value used to initiate the response was the same across experimental conditions. Only two of the six participants showed evidence for using the ROE strategy.
为了解规避和拦截动作的表现，了解人们如何决定何时发起动作很重要——在“正确”时刻发起动作通常是成功表现的关键。有人提出，当一个从感知中得出的量达到一个不变的标准值时，动作就会被触发。候选量包括碰撞时间（TTC）、距离和图像扩展率（ROE），所有这些都得到了实证支持。我们在一个计算机模拟的转向任务中研究了规避动作的发起，在这个任务中，观察者需要在一个静止的视觉环境中转向，并避免与路径上的障碍物相撞。那些提出规避动作发起基于TTC或距离的固定标准值的假设无法解释这些结果。然而，总体模式与使用标准ROE值是一致的。通过旨在直接评估用于发起反应的ROE值在不同实验条件下是否相同的分析，对此进行了进一步测试。六名参与者中只有两名显示出使用ROE策略的证据。
