McLeod R W, Ross H E
Perception. 1983;12(4):417-23. doi: 10.1068/p120417.
Time-to-collision (Tc) estimates were obtained from twenty-four subjects who viewed film clips for varying lengths of time. The film clips showed the view from a moving car travelling towards a stationary target car, but ended 100 m before reaching the target. Viewing time varied from 2 to 6 s, approach velocity from 40 to 100 km h-1, and Tc from 3.6 to 9.0s. It was hypothesised that, if time were needed to calculate Tc, the accuracy of Tc estimates would increase with viewing time up to some maximum. However, the results showed no effect of viewing time, and this was taken to indicate that estimates were based upon information directly available from the changing optic array at the eye of the observer. A significant velocity effect was found, accuracy increasing with velocity. Since velocity was inversely correlated with Tc, this probably implies that accuracy decreases with increasing Tc. Sex differences were found, with males giving higher and more accurate estimates than females. The relevance of these findings to the nature of Tc information is discussed.
碰撞时间（Tc）估计值来自24名观看不同时长电影片段的受试者。电影片段展示了一辆行驶的汽车驶向一辆静止目标汽车的视角，但在到达目标前100米处结束。观看时间从2秒到6秒不等，接近速度从40公里/小时到100公里/小时不等，Tc从3.6秒到9.0秒不等。假设如果需要时间来计算Tc，那么Tc估计的准确性会随着观看时间的增加而提高，直至达到某个最大值。然而，结果显示观看时间没有影响，这被认为表明估计是基于观察者眼睛处不断变化的光学阵列直接提供的信息。发现了显著的速度效应，准确性随着速度的增加而提高。由于速度与Tc呈负相关，这可能意味着准确性随着Tc的增加而降低。发现了性别差异，男性的估计值更高且更准确。讨论了这些发现与Tc信息性质的相关性。
