Filling your time: Auditory flutter alters perceived duration via stimulus-locked responses.

In the current article, we examined the flutter-duration illusion; the extension of perceived duration when an interval is filled with auditory flutter. Participants reproduced flutter-filled and empty durations while electrophysiological activity was recorded. As expected, participants over-produced durations when they were filled with auditory flutter rather than unfilled. Using multivariate pattern analysis, we found several differentiating patterns of neural activity while participants listened to either flutter-filled or empty intervals. However, in subsequent single trial analysis, only two of these clusters predicted perceived duration in the flutter condition; one occurring in line with the second click of the flutter, and one in line with the fourth click. We relate this finding to the N1P2 component and P3a component to timing initiation and arousal, respectively.

Can't catch the beat: Failure to find simple repetition effects in three types of temporal judgements.

More experience results in better performance, usually. In most tasks, the more chances to learn we have, the better we are at it. This does not always appear to be the case in time perception however. In the current article, we use three different methods to investigate the role of the number of standard example durations presented on performance on three timing tasks: rhythm continuation, deviance detection, and final stimulus duration judgement. In Experiments 1a and 1b, rhythms were produced with the same accuracy whether one, two, three, or four examples of the critical duration were presented. In Experiment 2, participants were required to judge which of four stimuli had a different duration from the other three. This judgement did not depend on which of the four stimuli was the deviant one. In Experiments 3a and 3b, participants were just as accurate at judging the duration of a final stimulus in comparison to the prior stimuli regardless of the number of standards presented prior to the final stimulus. In summary, we never found any systematic effect of the number of standards presented on performance on any of the three timing tasks. In the discussion, we briefly relate these findings to three theories of time perception.

What came before: Assimilation effects in the categorization of time intervals.

Assimilation is the process by which one judgment tends to approach some aspect of another stimulus or judgment. This effect has been known for over half a century in various domains such as the judgment of weight or sound intensity. However, the assimilation of judgments of durations have been relatively unexplored. In the current article, we present the results of five experiments in which participant s were required to judge the duration of a visual stimulus on each trial. In each experiment, we manipulated the pattern of durations they experienced in order to systematically separate the effects of the objective and subjective duration of stimuli on subsequent judgments. We found that duration judgments were primarily driven by prior judgments, with little, if any, effect of the prior objective stimulus duration. This is in contrast to the findings previously reported in regards to non-temporal judgments. We propose two mechanist explanations of this effect; a representational account in which judgments represent the speed of an underlying pacemaker, and an assimilation account in which judgment is based in prior experience. We further discuss results in terms of predictive coding, in which the previous rating is representative of a prior expectation, which is modified by current experience.

The Dawn of the Study of Motor Timing: Wilhelm Camerer (1866) and Karl von Vierordt (1868) on the Time Course of Voluntary Movements.

This article discusses material from the doctoral thesis of Wilhlem Camerer, which was devoted to the topic of the timing of voluntary movements, and appeared in 1866, thus being one of the earliest studies of any aspect of time perception. It was conducted under the supervision of Karl von Vierordt, at the University of Tübingen in Germany. The data reported come from Camerer's attempts to make a movement over a distance of about 65 mm, either by flexion or extension of his arm, with the behavior recorded via a kymograph, and measured from its trace. Most of his data come from his attempts to make movements at a constant speed, with the speed varying from one trial to another from 5 to 60 mm/s, but he also conducted a study where the movement was intended to be accelerated or decelerated during the trial. In general, when extension movements were intended to be performed with constant speed, a gradual increase in movement speed usually occurred throughout the movement duration. For flexions the opposite occurred, albeit less clearly. Camerer linked the apparent distortions of speed to Vierordt's experiments on the perception of time and his thesis contains what is probably the first mention of Vierordt's Law, the proposition that short times are judged as longer, and long times as shorter, than they really are.

"Time Slows Down Whenever You Are Around" for Women but Not for Men.

What happens when we unexpectedly see an attractive potential partner? Previous studies in laboratory settings suggest that the visualization of attractive and unattractive photographs influences the perception of time. The major aim of this research is to study time perception and attraction in a realistic social scenario, by investigating if changes in subjective time measured during a speed dating are associated with attraction. The duration of the dates was variable and participants had to estimate the time that passed. Among other measures, participants also rated the potential partners in terms of their physical attractiveness before and after the dates and reported if they would like to exchange contact with them. Results showed that, in a real speed dating situation, when there is a perception of the partner as being physically more attractive, women tend to overestimate the duration of that meeting, whereas men tend to underestimate its duration. Such changes may reflect evolutionary adaptations which make the human cognitive system more responsive in situations related to reproductive fitness.

Decisional carryover effects in interval timing: Evidence of a generalized response bias.

Decisional carryover refers to the tendency to report a current stimulus as being similar to a prior stimulus. In this article, we assess decisional carryover in the context of temporal judgments. Participants performed a temporal bisection task wherein a probe between a long and short reference duration (Experiment 1) was presented on every trial. In Experiment 2, every other trial presented a duration the same as the short or long reference duration. In Experiment 3, we concurrently varied both the size and duration of stimuli. Experiment 1 demonstrated the typical decisional carryover effect in which the current response was assimilated towards the prior response. In Experiment 2, this was not the case. Conversely, in Experiment 2, we demonstrated decisional carryover from the prior probe decision to the reference duration trials, a judgment which should have been relatively easy. In Experiment 3, we found carryover in the judgment of both size and duration, and a tendency towards decisional carryover having a larger effect size when participants were making size judgments. Together, our findings indicate that decisional carryover in duration judgments occur given relatively response-certain trials and that this effect appears to be similar in both size and duration judgments. This suggest that decisional carryover is indeed decisional in nature, rather than due to assimilative effects in perception, and that the difficulty of judging the previous test stimuli may play a role in whether assimilation occurs in the following trial when judging duration.

The expected oddball: effects of implicit and explicit positional expectation on duration perception.

The oddball duration effect describes how a rare stimulus amongst a string of standard stimuli is perceived to have a longer duration than the standards, even if they are of the same objective duration. Several theories have been proposed to explain this phenomenon. In order to adjudicate between opposing explanations, we have borrowed three extensively studied paradigms from the variable foreperiod literature: the sequential foreperiod, temporal cueing and a skewed foreperiod distribution. This approach allowed us to examine the effects of positional expectation on perceived oddball duration, while avoiding confounds from first-order positioning of the oddball in a sequence of standards. Through these three experiments, we demonstrate a clear role of positional expectation in the lengthening of the perceived duration of an oddball. We show that this expectation effect is separable from other drivers of the oddball duration illusion.

Executive processes and timing: Comparing timing with and without reference memory.

Temporal perception is influenced by executive function. However, performance on different temporal tasks is often associated with different executive functions. This study examined whether using reference memory during a task influenced how performance was associated with executive resources. Participants completed temporal generalisation and bisection tasks, in their normal versions involving reference memory and in episodic versions without reference memory. Each timing task had two difficulty levels: easy and hard. Correlations between performance on these tasks and measures of executive function (updating, inhibition, task switching, and access to semantic memory) were assessed. Accuracy on the temporal generalisation task was correlated with memory access for all versions of the task. Updating correlated with accuracy only for the reference memory-based version of the task. Temporal bisection performance presented a different pattern of correlations. The bisection point was negatively correlated with inhibition scores, except for the easy episodic condition. The Weber ratio, considered a measure of temporal sensitivity, was negatively correlated with memory access only in the hard episodic condition. Together, the findings suggest that previous models of generalisation and bisection may not accurately reflect the underlying cognitive processes involved in the tasks.

Differences in the temporal processing between identification and categorization of durations: A behavioral and ERP study.

This study examined how different forms of decision-making modulate time perception. Participants performed temporal bisection and generalization tasks, requiring them to either categorize a stimulus duration as more similar to short or long standards (bisection), or identify whether or not a duration was the same as a previously-presented standard (generalization). They responded faster in the bisection task than in the generalization one for long durations. This behavioral effect was accompanied by modulation of event-related potentials (ERPs). More specifically, between 500 ms and 600 ms after stimulus offset, a late positive component (LPC), appearing in the centro-parietal region, showed lower amplitude in the bisection task than in the generalization one, for long durations, mirroring the behavioral result. Before (200-500 ms) and after (600-800 ms) this window, the amplitude of the LPC was globally larger in the generalization paradigm, independently of the presented duration. Finally, the LPC amplitude was higher for long durations than for shorter ones at the beginning of the component (between 200 and 300 ms after stimulus extinction) and was then higher for short durations than for longer ones (between 300 and 600 ms after offset), indicating that the decision about the former stimuli was made earlier than for the latter ones. Taken together, these results indicate that the categorization of durations engages fewer cognitive resources than their identification.

Short-term effects on temporal judgement: Sequential drivers of interval bisection and reproduction.

Our prior experiences provide the background with which we judge subsequent events. In the time perception literature one common finding is that providing participants with a higher percentage of a particular interval can skew judgment; intervals will appear longer if the distribution of intervals contains more short experiences. However, changing the distribution of intervals that participants witness also changes the short-term, interval-to-interval, sequence that participants experience. In the experiment presented here, we kept the overall distribution of intervals constant while manipulating the immediately-prior experience of participants. In temporal bisection, this created a noted assimilation effect; participants judged intervals as shorter given an immediately preceding short interval. In interval reproduction, there was no effect of the immediately prior interval length unless the prior interval had a linked motor command. We thus proposed that the immediately prior interval provided a context by which a subsequent interval is judged. However, in the case of reproduction, where a subsequent interval is reproduced, rather than seen, the effects of contextualization are attenuated.

The differential recruitment of short-term memory and executive functions during time, number, and length perception: An individual differences approach.

Developmental, behavioural, and neurological similarities in the processing of different magnitudes (time, number, space) support the existence of a common magnitude processing system (e.g., a theory of magnitude, ATOM). It is, however, unclear whether the recruitment of wider cognitive resources (short-term memory, STM; and executive function) during magnitude processing is similar across magnitude domains or is domain specific. The current study used an individual differences approach to examine the relationship between STM, executive function, and magnitude processing. In two experiments, participants completed number, length, and duration bisection tasks to assess magnitude processing and tasks that have been shown to assess STM span and executive component processes. The results suggest that the recruitment of STM and executive resources differed for the different magnitude domains. Duration perception was associated with access, inhibition, and STM span. Length processing was associated with updating, and number processing was associated with access to semantic memory. For duration and length, greater difficulty in the magnitude judgement task resulted in more relationships to STM and executive function. It is suggested that duration perception may be more demanding of STM and executive resources because it is represented sequentially, unlike length and number which can be represented nonsequentially.

Passage of Time Judgments Are Not Duration Judgments: Evidence from a Study Using Experience Sampling Methodology.

This study examined relations between passage of time judgments and duration judgments (DJs) in everyday life, in young and elderly people, with an Experience Sampling Method. The DJs were assessed by verbal estimation and interval production measures. The results showed no difference between young and elderly people in judgments of rate of passage of time, a result contrary to the conventional idea that time passes more quickly as we get older. There were also no significant relation between the judgment of passage of time and the judgments of durations. In addition, the significant predictors of individual differences in the judgment of passage of time (emotion states and focus of attention on the current activity) were not predictors of judgment of durations. In sum, passages of time judgments are not related to DJs.

Experience Sampling Methodology reveals similarities in the experience of passage of time in young and elderly adults.

Many people accept the idea that time seems to pass more quickly as they get older, as if this is a psychological reality. However, systematic investigations of differences in judgments of passage of time between young and elderly people are very rare and contradictory. The present study examined the experience of passage of time in daily life in young and elderly people using Experience Sampling Methodology (ESM), with 8 alerts per day for 5 days being delivered by smartphones. At each alert, a short questionnaire was filled in, asking questions about passage of present time, affective state, arousal level, and attention to current activities, among others. Our ESM study found no difference between the young and the old participants in the judgment of passage of present time. Irrespective of the participants' age, the experience of passage of time in every-day life was significantly related to affective states and current activities when they captured attention.

The differential contribution of executive functions to temporal generalisation, reproduction and verbal estimation.

Evidence from dual-task studies suggests that executive resources are recruited during timing. However, there has been little exploration of whether executive recruitment is universal across temporal tasks, or whether different temporal tasks recruit different executive resources. The current study explored this further by examining how individual differences in updating, switching, inhibition and access affected performance on temporal generalisation, reproduction and verbal estimation tasks. It was found that temporal tasks differentially loaded onto different executive resources. Temporal generalisation performance was related to updating and access ability. Reproduction performance was related to updating, access and switching. Verbal estimation performance was only related to access. The results suggest that executive resources may be recruited when monitoring and maintaining multiple durations in memory at the same time, and when retrieving duration representations from long-term memory. The findings emphasise the need to consider timing behaviour as the product of a wide range of complex, integrated, cognitive systems, rather than as the output of a clock in isolation.

Females' duration estimates of briefly-viewed male, but not female, photographs depend on attractiveness.

We tested a prediction that females' duration estimates of briefly-viewed male, but not female, photos would be modulated by attractiveness. Twenty-seven female participants viewed sequences of five stimuli of identical duration in which the first four were sine-wave gratings (Gabor discs) and the fifth was either the same sine-wave grating (control trials) or a photo of an attractive or unattractive male or female (test trials). After each sequence, participants had to reproduce the duration of the fifth stimulus. Results confirmed our prediction and showed that duration estimates of attractive male photos were significantly longer than corresponding estimates for unattractive male photos, while there was no significant difference in estimated duration for attractive and unattractive female photos. Our data show that unexpectedly viewing an attractive male affects time perception in females, and are the first demonstration that stimuli relevant to reproductive fitness, which engage the appetitive motivational system, can increase perceived duration.

Explaining between-group differences in performance on timing tasks.

The article discusses interpretation of between-group differences in performance on timing tasks. First, it is shown that differences in internal clock "pacemaker speed" cannot normally be used as a coherent explanation of obtained effects, even if such differences in pacemaker speed exist. Secondly, it is shown how, in theory, modelling of performance on commonly used timing tasks like bisection and temporal generalization can illuminate between-group effects. Thirdly, the article discusses some examples of such modelling from published work and shows how some between-group differences--for example, between children of different ages, or between patients and controls--have been explained. Finally, some ambiguities in modelling are discussed--for example, the fact that different explanations of differences in performance on timing tasks between groups may be difficult or impossible to distinguish in practice.

The cognitive neuroscience of time perception: how psychological studies might help to dissect the timing system.

It is argued that the cognitive neuroscience of time perception does not make sufficient use of a range of experimental techniques and theoretical approaches which might be useful in "dissecting" the human timing system, and thus helping to uncover its neural basis. These techniques are mostly inspired by scalar expectancy theory, but do not depend on acceptance of that model. Most of the methods result in the same physical stimuli giving rise to systematically different time judgements, thus they avoid problems of control which have haunted some areas of the cognitive neuroscience of timing. Among the possibilities are (a) changing the basic duration judgement of stimuli and events, (b) manipulating working memory and reference memories for duration, and (c) changing temporal decision processes.

Interference between auditory and visual duration judgements suggests a common code for time.

Auditory stimuli usually have longer subjective durations than visual ones for the same real duration, although performance on many timing tasks is similar in form with different modalities. One suggestion is that auditory and visual stimuli are initially timed by different mechanisms, but later converted into some common duration code which is amodal. The present study investigated this using a temporal generalization interference paradigm. In test blocks, people decided whether comparison durations were or were not a 400-ms standard on average. Test blocks alternated with interference blocks where durations were systematically shorter or longer than in test blocks, and interference was found, in the direction of the durations in the interference blocks, even when the interfering blocks used stimuli in a different modality from the test block. This provides what may be the first direct experimental evidence for a "common code" for durations initially presented in different modalities at some level of the human timing system.

More consistent, yet less sensitive: interval timing in autism spectrum disorders.

Even though phenomenological observations and anecdotal reports suggest atypical time processing in individuals with an autism spectrum disorder (ASD), very few psychophysical studies have investigated interval timing, and the obtained results are contradictory. The present study aimed to clarify which timing processes function atypically in ASD and whether they are related to the ASD diagnostic profile. Visual, auditory, and cross-modal interval timing was assessed in 18 individuals with ASD using a repeated standards version of the temporal generalization task. The use of two different standard durations (600 and 1,000 ms) allowed for an assessment of the scalar property of interval timing in ASD, a fundamental characteristic of interval timing. The ASD group showed clearer adherence to the scalar property of interval timing than the control group. In addition, both groups showed the normal effect that auditory stimuli had longer subjective durations than visual ones. Yet, signal detection analysis showed that the sensitivity of temporal discrimination was reduced in the ASD group across modalities, in particular for auditory standards. Moreover, response criteria in the ASD group were related to symptom strength in the communication domain. The findings suggest that temporal intervals are fundamentally processed in the same way in ASD and TD, but with reduced sensitivity for temporal interval differences in ASD. Individuals with ASD may show a more conservative response strategy due to generally decreased sensitivity for the perception of time intervals.

Perception of short time scale intervals in a hypnotic virtuoso.

Previous studies showed that hypnotized individuals underestimate temporal intervals in the range of several seconds to tens of minutes. However, no previous work has investigated whether duration perception is equally disorderly when shorter time intervals are probed. In this study, duration perception of a hypnotic virtuoso was tested using repeated standard temporal generalization and duration estimation tasks. When compared to the baseline state, hypnosis affected perception of intervals spread around 600 ms in the temporal generalization task but did not alter perception of slightly longer intervals spread around 1000 ms. Furthermore, generalization of temporal intervals was more orderly under hypnosis than in the baseline state. In contrast, the hypnotic virtuoso showed a typical time underestimation effect when perception of longer supra-second intervals was tested in the duration estimation task, replicating results of the previous hypnosis studies.