Judging multi-minute intervals retrospectively

A total of 50 participants were asked to perform five different cognitive tasks lasting 120, 210, 300, 390 and 480 s, respectively. After completing the series of tasks, they were asked to estimate retrospectively the duration of each one. Psychophysical analyses linking psychological time to physical time revealed that the value of the power law exponent was about .47, but was .79 when the estimate of the total duration of the session was taken into account—a value lower than unity, indicating that shorter durations have been overestimated, and longer durations underestimated. The Weber fraction, or the ratio of variability to time, ranged from .59 (at 120 s) to .21 (at 480 s). Overall, the study shows that it is possible to make certain changes in the traditional retrospective timing method and thus adapt it for further investigations of the mechanisms involved in memory for the duration of past events.     

Temporal generalization under time pressure in humans

In two experiments, participants performed a temporal generalization task in which they were asked to decide whether or not the durations of comparison stimuli were different from those of standard stimuli (750 ms, 1,000 ms, or 1,250 ms). One half of the participants was instructed to respond as quickly as possible, while the other half received no instruction concerning the speed of response. The relationship between stimulus duration and the time of response and the effect of time pressure on duration discrimination were examined. Response time increased as a linear function of the duration of the to-be-judged stimuli until a certain instant, which was defined as T₂ = s/(1 - b), where s refers to the internal representation of the standard duration and b to the decision threshold. Moreover, the participants systematically overestimated the presented intervals if they were asked to respond as fast as possible when the standard duration was either 1,000 ms or 1,250 ms, but not when the standard duration was 750 ms.     

Prospective and retrospective time perception are related to mental time travel: Evidence from Alzheimer’s disease

Unlike prospective time perception paradigms, in which participants are aware that they have to estimate forthcoming time, little is known about retrospective time perception in normal aging and Alzheimer’s disease (AD). Our paper addresses this shortcoming by comparing prospective and retrospective time estimation in younger adults, older adults, and AD patients. In four prospective tasks (lasting 30 s, 60 s, 90 s, or 120 s) participants were asked to read a series of numbers and to provide a verbal estimation of the reading time. In four other retrospective tasks, they were not informed about time judgment until they were asked to provide a verbal estimation of four elapsed time intervals (lasting 30 s, 60 s, 90 s, or 120 s). AD participants gave shorter verbal time estimations than older adults and younger participants did, suggesting that time is perceived to pass quickly in these patients. For all participants, the duration of the retrospective tasks was underestimated as compared to the prospective tasks and both estimations were shorter than the real time interval. Prospective time estimation was further correlated with mental time travel, as measured with the Remember/Know paradigm. Mental time travel was even higher correlated with retrospective time estimation. Our findings shed light on the relationship between time perception and the ability to mentally project oneself into time, two skills contributing to human memory functioning. Finally, time perception deficits, as observed in AD patients, can be interpreted in terms of dramatic changes occurring in frontal lobes and hippocampus.     

Is the growth of subjective time in humans a linear or nonlinear function of real time?

The difficulties of deciding whether subjective time grows as a linear or nonlinear function of real time are discussed, and two experiments are presented to address this question. In Experiment 1, people received a 10-s standard duration and then had to judge what proportion other durations (ranging from 1 to 10 s) were of the standard. Counting was prevented by a concurrent task. The relation between judged and actual proportions was linear. In Experiment 2, people were required to average together three tone durations (mean duration 600 ms) and to judge whether subsequently presented comparisons were or were not the average. The spacing of the tone durations had no effect on judgements, suggesting a linear underlying time scale.     

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     

The time course of processing external and internal features of unfamiliar faces

The time course of processing internal and external facial features was studied in a sequential face matching task, where first a target face was presented, followed by a test face. The exposure duration of the test face was varied systematically (90, 120, 150 ms, and self-paced). In three tasks, participants were instructed to match either the whole face, only external features, or only internal features of the target and test face. Taken together, the results in all the three tasks provide evidence for very fast matching processes. For upright faces, maximal performance was achieved at 90 ms exposure duration and longer exposure durations (120, 150 ms, self-paced) did not improve accuracy. For inverted whole faces, reduced exposure duration resulted in an increase of matching errors, suggesting that below 150 ms of exposure duration, inverted faces cannot be matched reliably. When matching selected facial features only, no such inversion effect was found. Our data challenges previous claims that external features are matched faster than internal: no difference of time course was found between external and internal features. However, external features were matched more accurately.     

Establishing the Duration of Crimes: An Individual Differences and Eye‐Tracking Investigation into Time Estimation

The time available for viewing a perpetrator at a crime scene predicts successful person recognition in subsequent identity line‐ups. This time is usually unknown and must be derived from eyewitnesses' duration estimates. This study therefore compared the estimates that different individuals provide for crimes. We then attempted to determine the accuracy of these durations by measuring observers' general time estimation ability with a set of estimator videos. Observers differed greatly in their ability to estimate time, but individual duration estimates correlated strongly for crime and estimator materials. This indicates that it might be possible to infer unknown durations of events, such as criminal incidents, from a person's ability to estimate known durations. We also measured observers' eye movements to a perpetrator during crimes. Only fixations on a perpetrator's face related to eyewitness accuracy, but these fixations did not correlate with exposure estimates for this person. The implications of these findings are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

Cognitive abilities explaining age-related changes in time perception of short and long durations

The current study investigated how the development of cognitive abilities explains the age-related changes in temporal judgment over short and long duration ranges from 0.5 to 30 s. Children (5- and 9-year-olds) as well as adults were given a temporal bisection task with four different duration ranges: a duration range shorter than 1 s, two duration ranges longer than 3 s (4-8 s and >15 s), and an intermediate duration range (1.25-2.5 s). Their cognitive abilities were also assessed using a series of neuropsychological tests. The results showed that temporal sensitivity improved with age for each duration range but that this improvement occurred earlier for the short durations than for the long durations. Furthermore, the results revealed that the age-related improvement in time sensitivity for the durations shorter than 1 s was explained by the development of short-term memory span, whereas that for long durations was explained by the development of attention/executive functions. To summarize, the development of the abilities required to process long durations seems to be explained mainly by the development of attentional resources.     

Development of time sensitivity: Duration ratios in time bisection

This study investigated the development of children's abilities to discriminate durations as a function of their ratio and examined whether the ability to discriminate durations that differed by a very difficult ratio is related to the development of attention capacities. Children aged 5 and 8 years, as well as adults, performed a series of temporal bisection tasks with a ratio between the short and the long anchor duration that was changed to control the difficulty of the task (5:6, 2:3, and 1:2) in two duration ranges (<1 s and >3 s). In addition, they completed neuropsychological tests in order to assess their short-term memory, working memory, and visual attention abilities. The results showed that, at ratios of 2:3 and 1:2, most participants were able to discriminate the anchor durations in bisection. However, their sensitivity to time improved, whatever the duration range, both as the distance between the anchor durations increased and with increasing age. For the smallest duration ratio (5:6), few of the children were able to discriminate the anchor durations in the bisection task in comparison to adults. Hierarchical regression analyses performed on the neuropsychological tests revealed that, for the 2:3 ratio between anchor durations, the participants' visual attention scores explained a large part of the variance in time sensitivity. The children's lower temporal sensitivity was probably due to their limited visual attention abilities, thus explaining the difficulty they experienced in discriminating very close durations (5:6).     

学前儿童对短时时距的区分及其认知策略

本研究以令儿童比较时距长短为手段进一步探查学前（５、６岁）儿童对短时时距的认知过程,挖掘幼儿的认知潜力。研究结果表明：１）学前５、６岁儿童已能区分只有几秒钟差异的短时时距;２）６岁儿童已能使用时间标尺测量时间,５岁儿童已有潜力把时间看成是可以计数的维量;３）两时距的时间差别大小是影响儿童认知成绩的主要因素之一。     

Effects of sound-marker durations on rhythm perception

Our aim in this study was to examine the influence of sound-marker durations on the perception of simple rhythm patterns. These comprised three successive sounds marking two neighbouring time intervals, T1 and T2, with their onsets. We varied the durations of each of the three sound markers to make them either 20 or 60 ms. Durations of T1 and T2 were also varied, but the total duration of T1 and T2 was fixed at either 240 or 480 ms. In experiment 1, participants compared the durations of T1 and T2. In experiment 2, the subjective duration of each interval was measured separately. We found that lengthening the duration of the sound marker which terminated an interval increased the subjective duration of that interval: lengthening the duration of the second marker increased the subjective duration of T1, and lengthening the duration of the third marker increased the subjective duration of T2. Lengthening the duration of the first marker increased the subjective duration of T1 when T1 + T2 = 240 ms, especially when T1 > T2. This effect of first-marker duration, which could not be observed with single intervals used in the control conditions, seemed to enhance the contrast between T1 and T2. The effects of marker durations are associated with previous time-perception studies, in which single time intervals were used. They are discussed in the context of rhythm-perception studies, in which more complex sound patterns have been used.     

The role of learning in remembered duration

In two experiments, the effects of learning on both the accuracy and bias of duration judgments were examined. In Experiment 1, subjects learned one of two tasks (i.e., using a computer software package, building a model car), containing a varying number of action steps, over a one-, three-, or five-trial period. Retrospective judgments of a task’s total duration revealed that accuracy was high at intermediate stages of learning but was low at early stages due to an overestimation bias and low at later stages due to an underestimation bias. The number of action steps within a task influenced behavior only at early learning stages where more action steps led to significantly longer duration estimates. Experiment 2 acted as a converging operation in which novice and experienced pianists were asked to estimate, in advance, how long they thought it would take them to play melodies that varied in their degree of familiarity (i.e. recently learned, well learned, extremely well learned). When these estimates were compared with the melodies’ actual playing times, results revealed a similar pattern of accuracy and bias as found in Experiment 1. These findings are discussed in terms of a “structural remembering model” that emphasizes the role of event predictability in time estimation behavior.     

Static images with different induced intensities of human body movements affect subjective time

Modulation of subjective time was examined using static images eliciting perceptions of different intensities of body movement. Undergraduate students were exposed to photographs of dancer sculptures in different dance positions for 36 sec. and asked to estimate the exposure duration. Lower movement intensities were related to shorter estimated durations. Mean durations for images of unmoving dancers were underestimated and for dancers taking a ballet step were overestimated. Temporal estimations were also related to the order of presentation of the stimuli, which suggested that subjective time estimations were influenced by the experimental context. Subjective time is related not only to the visual perception of moving images, but also of elicited perceptions of movement in static images, suggesting an embodiment effect on subjective time estimation.     

Verbal working memory and planning: learning to compare movement durations of objects

Relations between duration judgments and verbal or visual working memory, between duration judgments and effect of learning to plan the processing of information about such judgments were investigated. A computer monitor was used to present images of two cars traveling in the same direction for various durations and distances. Participants (N=30) were asked to identify the car that had traveled for the longer duration. Then, participants learned how to solve Piagetian tasks logically. After the learning, they tried to solve the duration judgments task again. Finally, their verbal and visual working memory capacities were assessed. Results indicated the following: (a) numbers of correct answers on the Piagetian tasks were correlated with verbal and visual working memory capacity; (b) the correlations did not significantly decrease after the participants learned how to solve the Piagetian tasks.     

Relations between emotion,memory encoding,and time perception

This study examined duration judgments for taboo and neutral words in prospective and retrospective timing tasks. In the prospective task, participants attended to time from the beginning and generated shorter duration estimates for taboo than neutral words and for words that they subsequently recalled in a surprise free recall task. These findings suggested that memory encoding took priority over estimating durations, directing attention away from time and causing better recall but shorter perceived durations for taboo than neutral words. However, in the retrospective task, participants only judged durations in a surprise test at the end, and their duration estimates were longer for taboo than neutral words. Present findings therefore suggest that the same emotion-linked memory encoding processes can cause underestimation of durations in prospective tasks but overestimation in retrospective tasks, as if emotion enhances recall of ongoing events but causes overestimation of the durations of those events in retrospect.     

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。     

The Validity of Task Coverage Ratings by Incumbents and Supervisors: Bad News

In this study incumbents from three different jobs were asked to rate lists of their job tasks on various constructs (e.g., time, importance) and then estimate the percentage of their job tasks (task coverage) included in the task list. Incumbents made these ratings under one of two conditions. In two instances, two months after making an initial task coverage rating for the entire list of tasks, the same incumbents were asked to estimate the task coverage of a reduced list of tasks (i.e., half to two-thirds of the tasks were removed from the list presented for rating). In a third instance one group of incumbents completed an entire inventory while a second group completed a reduced inventory. The average task coverage rating for the entire inventories were high (percent estimates ranging in the 80's–90's) and the average of the reduced inventories was much higher than expected (percent estimates in the 70's). It was concluded that incumbents and supervisors were not able to accurately estimate task coverage.     

Processing two tasks with varying task order: central stage duration influences central processing order

In a recent study, Sigman and Dehaene (2006, PLoS Biology, 4, 1227–1238) reported that perceptual processing duration influences processing order of two tasks in the psychological refractory period paradigm (PRP). The present study examines whether the duration of central processes also influences processing order. For this purpose, we employed letter tasks with different central processing durations and varied task order in the PRP. In one part of the experiment, a tone discrimination task was combined with a similar time-consuming letter discrimination task. In the other part, the tone task was combined with a more time-consuming letter task, which required a mental rotation of the letter thereby prolonging central processing. If the duration of central processes influences processing order, participants should perform the tone task first more often when it is presented with the more time-consuming mental rotation task, than when it is presented with the similar time-consuming letter task. The results clearly confirm this prediction and thus show that not only perceptual processing duration but also central processing duration affects processing order in a dual-task situation. We suggest that the reported effect mirrors a tendency of participants to minimize total reaction time to both tasks by reducing slack time.     

Left hemisphere selectivity for processing duration in normal subjects

The role of the left cerebral hemisphere for the discrimination of duration was examined in a group of normal subjects. Two tasks were presented: the first required a reaction-time response to the offset of monaural pulse sequences varying in interpulse duration, and the second required the discrimination of small differences in durations, within a delayed-comparison paradigm. In each task a right-ear advantage was obtained when the durations were 50 msec or less. No ear advantage was obtained for the larger durations of 67 to 120 msec. Since the perceptual distinctiveness of phonemes may be provided by durations approximating 50 msec, the nature of the relationship between the left hemisphere's role in temporal processing and speech processing may be elaborated.     

Time counts: Bidirectional interaction between time and numbers in human adults

Number is known for influencing time processing, but to what extent time influences number in human adults is unclear. We investigated possible bidirectional interactions (number on time and time on number) using a novel Stroop-like task; participants compared numbers or temporal durations in congruent (larger number presented for longer duration) or incongruent conditions (smaller number presented for longer duration). Time and number tasks were presented in different blocks (Experiment 1) or within the same block of trials with task instructions provided at the offset of the stimuli (Experiment 2). Analyses of response times (RTs) and their distribution revealed that number affected time from early RTs, and time affected number at late RTs – an asymmetry observed only when time and number tasks were presented in separate blocks. Thus, carefully chosen tasks and appropriate data analysis can reveal bidirectionality between time and number, consistent with shared magnitude or decision mechanisms.