Hoffmann E R
Department of Mechanical and Manufacturing Engineering, University of Melbourne, Parkville, Victoria, Australia.
Perception. 1994;23(8):947-55. doi: 10.1068/p230947.
Subjects estimated time of vehicle arrival while viewing twenty-four film clips of an approaching vehicle, half with a constant viewing time of 4.2 s and half with a constant vehicle-movement distance of 40 m. The distances from the subject at which the film ended were 20, 60, and 100 m. Speeds of approach varied between 7.45 and 15.44 m s-1. Performance was strongly dependent on age of the subject. Subjects in the 5-6-year-old group made estimates based on the distance of the vehicle; at 7-8 years an interaction between the effects of distance and velocity appeared and for 9-10-year-olds there was a main effect of the vehicle velocity. Only for adults was the information from distance and velocity fully integrated. There was no significant difference between males and females for any of the age groups. Performance of adults was very similar to that reported by other authors in that subjects underestimated the time to arrival of the vehicle, with estimated times about 60% of the actual times. Standard deviations of the estimated times were such that a small percentage of subjects overestimated times and hence would have caused a collision if they had proceeded with a crossing. The mechanism of time estimation was strongly dependent on the angular velocity of the vehicle subtended at the eye of the observer. This must exceed a threshold value of about 0.002 rad s-1 (adults) if a linear relationship between estimated and actual times is to be obtained.
受试者在观看24个车辆接近的影片片段时估计车辆到达时间，其中一半片段的固定观看时间为4.2秒，另一半片段的车辆移动距离固定为40米。影片结束时车辆与受试者的距离分别为20米、60米和100米。接近速度在7.45至15.44米/秒之间变化。表现强烈依赖于受试者的年龄。5至6岁组的受试者根据车辆距离进行估计；7至8岁时，距离和速度的影响之间出现了相互作用，而9至10岁的受试者则主要受车辆速度的影响。只有成年人能够完全整合距离和速度信息。各年龄组的男性和女性之间均无显著差异。成年人的表现与其他作者报告的非常相似，即受试者低估了车辆到达时间，估计时间约为实际时间的60%。估计时间的标准差表明，一小部分受试者高估了时间，因此如果他们继续过马路就会导致碰撞。时间估计机制强烈依赖于观察者眼中车辆所张的角速度。如果要获得估计时间与实际时间之间的线性关系，这一角速度必须超过约0.002弧度/秒（成年人）的阈值。
