短时距估计中的标量特性

Scalar Property in Short Duration Estimation

使用单任务研究程序,采用预期式研究范式和再现时距的研究方法,从心理物理学的视角,通过三个实验系统地考查了人类短时距估计的标量特性、变异源、时距估计中的转换点和韦伯函数的形态等问题。结果表明,刺激物的运动、变化、速度和物理时距是被试进行短时距估计的重要变异源;被试在实验中表现出高估较短时距和低估较长时距的倾向,时距估计的转换点为11.1 s;计时过程中得到的韦伯函数是个分段连续函数,韦伯函数的拐点有两个12 s和21 s,这两点与本研究得到的时距估计转换点具有部分一致性。

This article thoroughly reviews the past literature and studies on time perception of a small range of durations. The scalar timing theory of Gibbon （1991） and collaborators, which emphasizes the importance of a central timekeeping mechanism, describes the origin and the function of scalar timing in human performance. Many experimental results support the idea that humans can have a favorite duration, that is, an interval length that gives a lower Weber fraction and maximum sensitivity. A transitional point, perhaps around 2s or less than 2s, decides subjects＇timing bias and reflects a fundamental time limitation of humans in processing information. The present study aims at investigating the scalar property and the source of variance in short duration （6s -24s） estimation. Based on the previous studies, we used the single-task program and incorporated the prospective paradigm in this study. From the perspective of psychophysics and by using a duration reproduction method, three experiments were conducted to investigate the scalar property, the source of variance, the transitional point, and the nature of the Weber function in temporal process of humans. The intervals ranging from 6s to 24s were selected and used as physical durations in the experiments, and a geometric stimulus was presented in visual mode on the computer screen. Fifty-five participants volunteered in the experiments, and all the participants were tested individually in sessions that lasted 50 ~ 60 minutes. The analysis of variance was then conducted on the data collected from these experiments. The experimental results showed that the motion status （ kinetic or static） and the rotating angles significantly affected the participants＇temporal judgments. Compared with the static conditions, the effects of kinetic stimulus were more significant. With the increase of rotating angles, the accuracy of duration estimation was increased. Physical durations of stimulus also showed a significant duration-lengthened effect. The speed of stimulus was another important cue used by the participants in estimating durations. The experimental results indicated that lower Weber fractions and the maximum time sensitivity for intervals were in 9s to 12s, and a transitional point occurred at 11. ls where the Weber fraction began to increase with longer durations. In contrary to overestimation of the shorter durations, the participants underestimated the longer durations. Three major conclusions are derived from this study. First, the motion status, speeds, changes （rotating angles） of stimulus, and physical durations are the main source of variance of temporal judgment. Second, people consistently overestimate the shorter durations and underestimate the longer durations. The transitional point in duration estimation is 11.1 s in the range 6s to 24s. Presenting sequences of intervals to humans not only affects the Weber function but also distorts perceived durations. Third, a piecewise continuous function is the best explanation for the Weber function. Inflectional points of the Weber function （12s and 21s） derived from this study are, to some extent, consistent with the transitional point of 11. ls in duration estimation.