短时距估计中刺激物的动态变化效应

用两个实验考查了时距估计中刺激物的动态变化效应。结果发现,刺激物的运动、速度和旋转角度显著地影响着被试的时间判断,刺激物速度的时距延长效应对于较长时距(18s-24s)来说更加明显;运动刺激与较短、较准确的时距判断相关联;旋转角度的减少使得被试低估时距,而旋转角度的增加使得时距估计呈高估倾向。被试在时间估计过程中表现出长时距低估和短时距高估现象,本研究得到的时间估计转换点是11.4s,此点与先前的有关研究基本一致。     

短时距估计中的心理影响因素

使用单任务研究程序,预期式研究范式,以产生时距作为反应指标,通过两个实验考察短时距估计中的间断位置、间断时距和提示线索效应,探讨产生时距与等待时距的关系问题,揭示注意和间断期望对短时距估计的影响。研究结果表明, 间断实验中表现出极其显著的提示线索效应,间断位置（等待时距）效应显著,间断时距效应及间断位置与间断时距的交互效应不显著。由此得出：(1)注意是影响被试时间判断的主要因素,被试的产生时距随着等待时距的增加而延长。(2)被试对间断的期望显著地影响其时间估计行为,无间断实验条件下,间断期望有损于时间估计。     

短时距标量计时模型的建构研究

采用预期式研究范式,创造性地使用单任务研究程序,从心理物理学的视角,通过六个实验系统地考查了影响被试短时距(6s至24s)估计的标量特性和物理、心理和生理的信息源因素.深入探讨了注意、激活、间断和间断期望效应因素对时间估计行为的影响及时序信息的动态加工过程.在此基础上,包含时钟、累加、记忆和比较四个动态加工过程的短时距标量计时模型得以建构.     

时距估计年龄差异的认知机制

采用双任务的实验范式,通过对（5s、13s和26s）三个目标时距的产生法和复制法的结果来探讨时距估计年龄差异的认知机制。实验结果表明,在不同目标时距和不同的估计方法上均存在显著的年龄效应。年老被试在产生法上比年轻被试显著高估时距,存在非时间任务和年龄的交互作用,随着任务难度的增加年老被试会比年轻被试产生更长的时距。而在复制法上年老被试比年轻被试显著低估时距,但是只有在长时距条件下（26s）存在非时间任务和年龄的交互作用。本研究结果表明年老被试在产生法上对时距的高估可能与内部时钟减慢和注意资源减少有关,而在复制法上对时距的低估可能反映注意资源的减少。此外,对于长时距的时间复制,情节记忆的损伤也是导致时距估计年龄差异的一个可能原因。     

时距估计任务中的间断期望效应

使用单任务研究程序,采用引入提示线索的方法,以产生时距作为反应指标对存在间断的时距估计任务中的间断期望效应和提示线索效应（注意效应）进行系统考察,并对间断时距的效应、产生时距与等待时距的关系问题作出进一步探讨。结果表明,间断位置（等待时距）因素是被试时间判断的主要线索,被试的产生时距随着等待时距的增加而延长。间断实验中表现出极其显著的提示线索效应,此效应既增加了时距估计的变异,又延长了被试的时距估计。无间断实验条件下,被试表现出显著的间断期望效应,被试对间断的期望有损于时间估计。     

预期式时距估计年龄差异的初步研究

以5s、13s和26s为目标时距,采用产生法和复制法,探讨了预期式条件下时距估计的年龄差异。结果表明在单任务作业中。年老被试和年轻被试两个年龄组之间估计时距的平均值没有显著差异,但年老被试比年轻被试的估计时距具有更大的变异性。单一的内部时钟频率变化的假设并不能对单任务条件下时距估计的年龄差异做出合理的解释。时距估计的年龄差异可能是内部时钟频率变化和认知过程变化交互作用的结果。     

时距估计中的锚定效应

采用两种时距估计方法,检验时距锚定值对时距估计的影响,并探讨了时距信息的心理表征方式。63名在校大学生参加了本次实验。实验1采用口头报告法,表明较大的时距锚定值（5s,5000ms）条件下,被试估对时距的估计值较大,而较小时距锚定值（1s,1000ms）条件下被试估计的时距值较小;语义相同但表述方式不同的锚定值（1s与1000ms,5s与5000ms）条件下的时距估计值没有显著差异。实验2采用产生法,进一步表明时距表述方式对产生时距没有显著影响。以上结果表明,时距估计受时距锚定值的影响,时距信息可能以语义形式进行表征,而不是简单的数字加单位的表层表征形式     

中央执行子功能对预期式时距估计的作用——基于结构方程模型的结果

采用结构方程模型的方法探讨中央执行系统与时距加工过程的关系,考察三种中央执行子功能(转换,抑制,刷新)对预期式长、短时距估计(两种标准时距:2s,5s)的作用模式。结果发现刷新功能对长、短时距估计任务都产生影响;抑制功能只作用于长时距估计;转换功能不参与单独的预期式时距估计过程。结果表明,三种执行子功能对预期式短时距加工和长时距加工的作用不同,支持时距加工的差异机制假设。     

1～6秒时距认知分段性特征

时距认知分段性指不同长度时距的加工机制和表征方式是不同的。以往研究者对1 s以上时距认知的分段性仍存在分歧,为了探讨这一主题,本研究设计了实验1和实验2。实验1采用时间复制任务比较高、低工作记忆容量被试在完成1~6 s视、听时距加工的成绩,结果发现,时距长度与工作记忆容量或通道均存在交互作用,被试在复制1 s、2 s的平均复制时距、复制比率及变异系数没有随工作记忆容量或通道而变化,而复制3 s、4 s、5 s及6 s时,高WMC组较低WMC组或听觉组较视觉组,平均复制时距显著更长、复制比率显著更高、变异系数显著更小。实验2采用时间产生任务比较高、低工作记忆容量被试在完成1~6 s视、听时距加工的成绩,结果也发现,时距长度与工作记忆容量或通道均存在交互作用,被试在产生1 s、2 s的平均产生时距、产生比率及变异系数没有随工作记忆容量或通道而变化,而产生3 s、4 s、5 s及6 s时,高WMC组较低WMC组或听觉组较视觉组,平均产生时距显著更短、产生比率显著更低、变异系数显著更小。这意味着1~6 s的时距认知存在分段性,大约2~3 s可能为分段临界点。时间认知的分段性可以用时间工作记忆说解释,该假说是时间认知分段综合模型解释短时距加工分段性的具体表现形式。     

听觉经验缺失对时距估计影响的实验研究

采用复制法,通过聋人与听力正常人时距估计的对比实验研究,结果发现听觉经验缺失对时距估计有一定的影响：（1）两类被试在2000ms和10000ms的时距估计中,再现时距的平均数表现出了显著性差异。听力正常被试倾向于低估时距,聋人被试倾向于高估时距。（2）聋人被试不同时距再现相对误差率之间不存在显著性差异;听力正常被试时距再现相对错误率在2000ms与10000ms、30000ms存在显著差异,10000ms和30000ms之间差异不显著。     

Scalar properties in human timing: Conformity and violations

Data from studies of timing in human participants were reviewed with respect to their conformity to the two scalar properties of timing: mean accuracy and the scalar property of variance. Results reviewed were taken from studies of temporal generalization, temporal bisection, discrimination methods, and “classical” timing tasks such as the reproduction, production, and verbal estimation of duration. Evidence for one or both scalar properties was found in many studies, including those using children and elderly participants, but systematic violations were sometimes noted. These violations occurred (a) when very short durations (<100 ms) were timed, (b) in situations in which timing tasks varying in difficulty were compared, (c) when classical timing tasks were employed, and (d) in situations where highly practised observers exhibited unusual patterns of variance. A later section attempted to reconcile some of these violations with an underlying scalar-consistent timing mechanism.     

Scalar properties in human timing: conformity and violations

Data from studies of timing in human participants were reviewed with respect to their conformity to the two scalar properties of timing: mean accuracy and the scalar property of variance. Results reviewed were taken from studies of temporal generalization, temporal bisection, discrimination methods, and "classical" timing tasks such as the reproduction, production, and verbal estimation of duration. Evidence for one or both scalar properties was found in many studies, including those using children and elderly participants, but systematic violations were sometimes noted. These violations occurred (a) when very short durations (< 100 ms) were timed, (b) in situations in which timing tasks varying in difficulty were compared, (c) when classical timing tasks were employed, and (d) in situations where highly practised observers exhibited unusual patterns of variance. A later section attempted to reconcile some of these violations with an underlying scalar-consistent timing mechanism.     

Human performance on an analogue of an interval bisection task

Two experiments used normal adult human subjects in an analogue of a time interval bisection task frequently used with animals. All presented durations were defined by the time between two very brief clicks, and all durations were less than 1 sec, to avoid complications arising from chronometric counting. In Experiment 1 different groups of subjects received standard durations of either 0.2 and 0.8 or 0.1 and 0.9 sec and then classified a range of durations including these values in terms of their similarity to the standard short (0.2- or 0.1-sec) and long (0.8- or 0.9-sec) durations. The bisection point (defined as the duration classified as "long" on 50% of trials) was located at 0.43 sec in the 0.2-0.8 group, and at 0.46 sec in the 0.1-0.9 group. Experiment 2 replicated Experiment 1 using a within-subject procedure. The bisection point of both 0.2- and 0.8 sec and 0.1- and 0.9-sec durations was found to be 0.44 sec. Both experiments thus found the bisection point to be located at a duration just lower than the arithmetic mean of the standard short and long durations, rather than at the geometric mean, as in animal experiments. Some other performance measures, such as difference limen, and Weber ratio, were, however, of similar values to those found in bisection tasks with animals. A theoretical model assuming that humans bisect by taking the difference between a presented duration and the short and long standards, as well as having a bias to respond "long", fitted the data well. The model incorporated scalar representations of standard durations and thus illustrated a way in which the obtained results, although different from those found with animal subjects, could be reconciled with scalar timing theory.     

Counting processes in human timing

A subject reproducing a long duration, t, may time out either a single interval of duration t or a succession of n intervals, each of duration t/n. It is shown that a class of timing models obeying Weber’s law predicts the variance of reproductions of t to be a decreasing function of the number of subdivisions, n. In contrast, a second class of proportional variance models, which includes Creelman’s pulse counter model (1962), predicts no change in the variance as a function of n. Data are presented from a duration reproduction experiment in which subjects counted silently at a specified rate up to a given number and then responded. Several statistics involving the variance of the reproduced durations are shown to be predicted significantly better by the Weber’s law class of models than by the proportional variance class of models.     

When are semantic targets detected faster than visual or acoustic ones?

Duration-discrimination data from an experiment using empty auditory intervals in a two-alternative forced-choice paradigm are presented. The observed functional relationship between standard deviation of the psychometric density function and stimulus duration is shown to be fit significantly better by a Weber’s law model of duration discrimination than by Creelman’s counter model. Both models fail to predict the rapid rise in the Weber fraction observed for durations longer than about 2 sec. However, the Weber’s law model, based on a generalization of Weber’s law, accurately predicts the initial drop in the Weber fraction for very short durations and the observed constancy of the Weber fraction for durations up to 2 sec.     

Scalar properties in animal timing: conformity and violations

The article reviews data from animal subjects on a range of timing tasks (including fixed-interval and temporal differentiation schedules, stimulus timing, aversive conditioning, and Pavlovian methods) with respect to conformity to the two scalar properties of timing behaviour: mean accuracy and scalar (Weberian) variance. Systematic deviations were found in data from temporal differentiation schedules, timing of very short (<100 ms) or very long (>100 s) durations, effects of "task difficulty", and some special cases where circadian and interval timing seemed to interact, or where some specific durations seemed to be timed more precisely than others. Theoretical reconciliation of some of these deviations with underlying scalar timing can be achieved, but a number of problematical cases remain unexplained.     

Scalar properties in animal timing: Conformity and violations

The article reviews data from animal subjects on a range of timing tasks (including fixed-interval and temporal differentiation schedules, stimulus timing, aversive conditioning, and Pavlovian methods) with respect to conformity to the two scalar properties of timing behaviour: mean accuracy and scalar (Weberian) variance. Systematic deviations were found in data from temporal differentiation schedules, timing of very short (<100 ms) or very long (>100 s) durations, effects of “task difficulty”, and some special cases where circadian and interval timing seemed to interact, or where some specific durations seemed to be timed more precisely than others. Theoretical reconciliation of some of these deviations with underlying scalar timing can be achieved, but a number of problematical cases remain unexplained.     

The perception of empty and filled time intervals by pigeons

Pigeons were trained in a within-subjects design to discriminate durations of a filled interval (2 s and 8 s of light) and durations of an empty interval (2 s and 8 s bound by two 500-ms light markers). Filled intervals required a response to one set of comparisons (e.g., blue vs. yellow), whereas empty intervals required a response to a different set of comparisons (e.g., red vs. green). Psychophysical testing indicated that empty intervals were judged to be longer than equivalent durations of a filled interval. This finding was replicated when the anchor durations used during training were changed to 1 s and 4 s, or 4 s and 16 s. The difference between the point of subjective equality (PSE) for the empty intervals and the PSE for filled intervals increased as the magnitude of the anchor duration pairs increased. In addition, the difference limens (DL) for empty intervals were smaller than those for filled intervals, and they also increased as the magnitude of anchor duration pairs increased. An analysis of the Weber fractions (WF; i.e., DL/PSE) provided evidence for superimposition of the empty and filled timing functions across the different sets of anchor durations. These results suggest that the accumulation of subjective time was greater for empty intervals than for filled intervals. Within the framework of scalar timing theory, this difference in timing appeared to be the result of a clock rate difference rather than a switch latency difference.     

Scalar timing without reference memory? Episodic temporal generalization and bisection in humans

Three experiments tested whether the scalar property of timing could occur when humans timed short durations under conditions in which it was unlikely that they developed reference memories of temporal "standards". Experiment 1 used an episodic version of a temporal generalization task where judgements were made of the potential equality of two durations presented on each trial. Unknown to the subject, one of these was always 200, 400, 600, or 800 ms, and the other was of variable duration. Temporal generalization gradients showed the scalar property of superimposition at standard values greater than 200 ms. Experiment 2 used a variant of the "roving bisection" method invented by Rodriguez-Girones and Kacelnik (1998) modified so that the scalar property of timing could be observed empirically. Data from bisection with short/long standard pairs of 100/400, 200/800, and 300/1,200 ms showed nearly perfect scalar-type superimposition. Experiment 3 again used episodic temporal generalization, but durations were never repeated and came from three distinct time ranges. Superimposition was found across these ranges except for the shortest visual stimuli timed. The data suggested that scalar timing could occur in humans in conditions where the formation of reference memories of temporal standards was highly improbable.