时间加工与空间距离加工的关系主要有两种,一种是在空距离-空时 距以及动物的研究中,时间加工影响空间距离加工,空间距离加工影响时间加工,两者相互影响,存在对称的干扰,这种关系与注意和记忆有关.另一种是在实距离 一实时距中,空间距离加工影响时间加工,而时间加工不受空间距离加工的影响,时间加工和空间距离加工之间具有不对称的干扰.时空关系的不对称与隐喻理论、 人们的感知运动经验和时空信息的显著性有关.神经机制上,右顶叶皮质、侧顶内区、左项叶皮质、小脑、前额等参与时间加工和空间距离加工,但两种加工涉及到 的神经机制也有部分差异.未来可以从时间加工的分段性、不同条件下时间加工和空间距离加工的心理机制以及脑机制进行研究.

时间知觉包括时距知觉和时序知觉。时距知觉的理论模型主要包括：起搏器累加器模型、资源分配模型、记忆衰减模型和状态依赖网络模型；时序知觉的认知机制主要包括：中枢计时机制、特定特征机制和信息强度假设；同时考虑时距和时序加工的综合模型包括：层级周期振荡模型和时间认知分段综合模型。未来将在探明时间知觉与意识的关系、扩展时间知觉的应用领域以及多学科交叉和多方法结合探索机理上可能有大的进展。

目的 了解老年人在不同加工水平和不同估计方法下回溯式时距估计的特点.方法 随机抽取某大学和某老年大学被试共32人,各16人,采用自编计算机程序进行实验.实验包括文字判断和时距估计两个任务,结束后进行访谈.结果 文字判断任务中,反应时的年龄主效应显著[F(1,28) =12.191,P＜0.01],加工水平主效应显著[F(1,28) =22.889,P＜0.001],其余效应均不显著.时距估计任务中,年龄主效应显著[F(1,24)=10.858,P＜0.05],其余效应均不显 著.两个年龄组时距估计比率分数均小于1,年轻组差异系数为0.22,年老组差异系数为0.21.结论 两个年龄组被试都倾向低估刺激时距；时距估计的年龄差异显著,表现为年老组显著长于年轻组,但更准确；加工水平和估计方法对时距估计影响不显著.

情绪极易影响时距知觉,致使主观时距偏离客观时距。新近研究者们结合日趋成熟的标量计时模型及神经学相关依据,并通过采用标准化情绪诱发材料的实验研究,较为系统地解释了情绪的生理唤醒和注意唤醒两种成分各自对内部计时机制造成的干扰效应。研究发现,两种效应中前者会加长主观时距而后者会使其缩短,且分别有不同的发生特点。该文在介绍国内外关于时距知觉中的情绪效应的新近研究基础上,提出应从探索两种效应的分离方法、考虑记忆效应因素以及增加实验自变量的数目和取值水平三个方面来开展进一步的研究。

以64名大学生为被试,使用对汉字进行知觉判断的任务,探讨熟悉度、时距估计方法、性别和加工深度对回溯式时距估计的影响。结果发现:(1)熟悉度对回溯式时距估计没有影响。(2)相对于结构加工任务,被试更加倾向于低估意义加工任务的时距。(3)在结构加工任务中,复制法的时距估计误差绝对值小于口头估计法。(4)男性在结构加工任务中的时距估计误差小于女性。研究表明熟悉度对时距估计的影响可能并非普遍现象。

采用回溯式时距估计的实验范式,以9s为目标时距,采用加工深度 作业,考察时距估计的年龄差异.结果表明年老组比年轻组显著高估目标时距,而加工深度作业并没有影响时距估计作业.回溯式时距估计的年龄差异可能与年老被 试较慢的加工速度或更快的遗忘率有关,其原因可能在于年老被试加工资源的减少.

采用回溯式实验范式探讨时距估计的年龄差异.以9s为目标时距,通过操纵目标时距内呈现刺激 的数量(4或7个数字或字母)(实验一)和分割的数量(1或4个分割数)(实验二),比较两个年龄组估计时距的差异.实验结果表明存在显著的年龄差异.存 储容量对年老被试时距估计的影响可以在于较慢的加工速度,而分割数量的影响可能与年老被试对情节记忆信息的编码和提取的失败有关,其根本原因可能在于年老 被试在加工刺激时无法抑制与任务无关的信息,从而导致比年轻组编码更多的背景信息或者无法提取背景信息,产生不同实验条件下结果的差异.

注意一直是时间知觉研究的一个重要问题.本文综述了研究已经取得 一些较为一致的结果:在双任务程序中对时间任务的注意越多,时距估计越准确;在单一任务中对目标刺激的时间属性注意越多,对该刺激的持续时距估计越准确; 在时间导向任务中,个体可以有效地、主动把注意导向未来的某段时距,那么将对出现在那个时刻的刺激做出更好的反应.最后,讨论了现有研究中存在的、以及今 后研究中需要着重考虑的问题.

78 We investigated the effect of reward on timing behavior using the peak procedure. 78 We also investigated its interaction with COMT, DRD2, and DAT gene polymorphisms. 78 Results show earlier timed response initiations when expecting larger rewards. 78 This effect was specific to certain COMT–DRD2 polymorphism combinations. 78 There was no effect of DAT gene polymorphisms.

Over recent decades, the study of the telling of history has emphasized the relationship of narrative structure and history. Inspired by the work of Hayden White (1975), this literature demonstrates t

Children's time estimation literature lacks of studies comparing prospective and retrospective time estimates of long lasting ecological tasks, i.e. tasks reflecting children's daily activities. In the present study, children were asked to estimate prospectively or retrospectively how much time they played a video game or read a magazine. Regardless of the task, the results revealed that prospective time estimates were longer than the retrospective ones. Also, time estimates of the video game task were longer, less accurate and more variable than those of the reading task. The results are discussed in the light of the current literature about time estimation of long lasting ecological tasks.

Abstract This article provides a selective review of time perception research, mainly focusing on the authors' research. Aspects of psychological time include simultaneity, successiveness, temporal order, and duration judgments. In contrast to findings at interstimulus intervals or durations less than 3.0-5.0 s, there is little evidence for an "across-senses" effect of perceptual modality (visual vs. auditory) at longer intervals or durations. In addition, the flow of time (events) is a pervasive perceptual illusion, and we review evidence on that. Some temporal information is encoded All rights reserved. relatively automatically into memory: People can judge time-related attributes such as recency, frequency, temporal order, and duration of events. Duration judgments in prospective and retrospective paradigms reveal differences between them, as well as variables that moderate the processes involved. An attentional-gate model is needed to account for prospective judgments, and a contextual-change model is needed to account for retrospective judgments. Copyright 2013 Elsevier B.V. All rights reserved.

We quantitatively reviewed human sex differences in the magnitude and variability of duration judgments. Data from 4,794 females and 4,688 males yielded 87 effect size estimates of magnitude and 28 of variability. The overall sex difference in duration judgment magnitude was small but statistically significant. It was moderated by whether study participants knew in advance (prospective paradigm) or only later (retrospective paradigm) that they would be required to judge duration. Although prospective judgments showed no overall sex effect, some levels of moderator variables showed a small but statistically significant effect. Retrospective judgments showed a larger subjective-to-objective duration ratio for females than for males, and several variables moderated this effect. Females’ judgments also showed more intersubject variability than did males’ judgments. Relative to males, females sustain attention to time more in the prospective paradigm and have better episodic memory in the retrospective paradigm.

A meta-analysis of 117 experiments evaluated the effects of cognitive load on duration judgments. Cognitive load refers to information-processing (attentional or working-memory) demands. Six types of cognitive load were analyzed to resolve ongoing controversies and to test current duration judgment theories. Duration judgments depend on whether or not participants are informed in advance that they are needed: prospective paradigm (informed) versus retrospective paradigm (not informed). With higher cognitive load, the prospective duration judgment ratio (subjective duration to objective duration) decreases but the retrospective ratio increases. Thus, the duration judgment ratio differs depending on the paradigm and the specific type of cognitive load. As assessed by the coefficient of variation, relative variability of prospective, but not retrospective, judgments increases with cognitive load. The prospective findings support models emphasizing attentional resources, especially executive control. The retrospective findings support models emphasizing memory changes. Alternative theories do not fit with the meta-analytic findings and are rejected.

This article reports a meta-analytic review of seven extant experiments, w i th 235 participants, concerning effects of physical workload on duration judgments. It also provides a qualitative assessment of related studies that, for specific reasons, were not includable in the quantitative meta-analysis. All analyzed experiments used the prospective duration-judgment paradigm and the production method, in which participants knew in advance that duration estimation was required. A large overall effect size reveals that increasing physical workload results in longer prospective duration productions. Physical workload effects are comparable to those of cognitive load. Implications for applied research, theory, and applications are discussed.

ABSTRACT This chapter describes a research that investigated the attentional modulation of time perception. It explains that this research involved various techniques for modifying attention to time including manipulations of temporal awareness and variations in the nature of the distractor tasks. All of the different approaches produced a consistent set of findings which indicate that interval timing requires attentional resources and that time judgement performance is influenced strongly by the allocation of those resources.

Five experiments examined whether changes in the pace of external events influence people’s judgments of duration. In Experiments 1a–1c, participants heard pieces of music whose tempo accelerated, decelerated, or remained constant. In Experiment 2, participants completed a visuo-motor task in which the rate of stimulus presentation accelerated, decelerated, or remained constant. In Experiment 3, participants completed a reading task in which facts appeared on-screen at accelerating, decelerating, or constant rates. In all experiments, the physical duration of the to-be-judged interval was the same across conditions. We found no significant effects of temporal structure on duration judgments in any of the experiments, either when participants knew that a time estimate would be required (prospective judgments) or when they did not (retrospective judgments). These results provide a starting point for the investigation of how temporal structure affects one-off judgments of duration like those typically made in natural settings.

Abstract BACKGROUND: Violence is a major concern and is prevalent across several mental disorders. The use of substances has been associated with an exacerbation of psychiatric symptoms as well as with violence. Compared to other substances such as alcohol and cocaine, existing literature on the cannabis-violence relationship has been more limited, with most studies being conducted in the general population, and has shown controversial results. Evidence has suggested a stronger relationship when examining the effects of the persistency of cannabis use on future violent behaviors. Though, while cannabis use is highly prevalent amid psychiatric patients, far less literature on the subject has been conducted in this population. Hence, the present prospective study aims to investigate the persistency of cannabis use in psychiatric patients. METHOD: The sample comprised of 1,136 recently discharged psychiatric patients provided by the MacArthur Risk Assessment Study. A multi-wave (five-assessment) follow-up design was employed to allow temporal sequencing between substance use and violent behaviors. Generalized estimating equations (GEE) were used to examine the effect of persistency of cannabis use on violence, while controlling for potential confounding factors. Potential bidirectional association was also investigated using the same statistical approach. RESULTS: Our results suggest a unidirectional association between cannabis use and violence. GEE model revealed that the continuity of cannabis use across more than one time wave was associated with increased risks of future violent behavior. Patients who reported having used cannabis at each follow-up periods were 2.44 times more likely to display violent behaviors (OR090009=0900092.44, 95% CI: 1.06-5.63, p 090009<0900090.05). CONCLUSION: These findings are particularly relevant as they suggest that the longer individuals report having used cannabis after a psychiatric discharge, the more likely they are of being violent in the following time waves. These results add to our understanding of the negative consequences of chronic cannabis use amid psychiatric patients.

Abstract Our sense of time is altered by our emotions to such an extent that time seems to fly when we are having fun and drags when we are bored. Recent studies using standardized emotional material provide a unique opportunity for understanding the neurocognitive mechanisms that underlie the effects of emotion on timing and time perception in the milliseconds-to-hours range. We outline how these new findings can be explained within the framework of internal-clock models and describe how emotional arousal and valence interact to produce both increases and decreases in attentional time sharing and clock speed. The study of time and emotion is at a crossroads, and we outline possible examples for future directions.

Retrospective time estimation is an important aspect of dynamic systems and needs to be integrated in cognitive architectures. This article gives an overview of theoretical accounts of retrospective and prospective time estimation. Assumptions based on an experiment investigating retrospective time estimation conducted in our research group are presented. Integrating both we introduce a retrospective timer-module for ACT-R 6.0 and the corresponding estimation algorithm. The successful validation of the module is shown and further implications are discussed.

Abstract The authors investigated retrospective timing in participants with Korsakoff's syndrome. Patients were assessed on four retrospective tasks on which they were instructed to read three-digit numbers aloud (15 seconds), fill connected squares (30 seconds), decide whether words were abstract or concrete (45 seconds), or read aloud a text about mushroom picking (60 seconds). Participants were not aware of the task's timing until the end of the tasks, when they were asked to estimate the elapsed time. Results revealed an underestimation of the elapsed time in Korsakoff participants, suggesting that time is perceived to pass quickly for these participants.

SEVERAL MODELS OF TIME ESTIMATION HAVE BEEN developed in psychology; a few have been applied to music. In the present study, we assess the influence of the distances travelled through pitch space on retrospective time estimation. Participants listened to an isochronous chord sequence of 20-s duration. They were unexpectedly asked to reproduce the time interval of the sequence. The harmonic structure of the stimulus was manipulated so that the sequence either remained in the same key (CC) or travelled through a closely related key (CFC) or distant key (CGbC). Estimated times were shortened when the sequence modulated to a very distant key. This finding is discussed in light of Lerdahl's Tonal Pitch Space Theory (2001), Firmino and Bueno's Expected Development Fraction Model (in press), and models of time estimation.

Annu Rev Psychol. 1984;35:1-36. Review

Cardiac signals reflect the function of the autonomic nervous system (ANS) and have previously been associated with a range of self-regulatory behaviors such as emotion regulation and memory recall. It is unknown whether cardiac signals may also be associated with self-regulation in the temporal domain, in particular impulsivity. We assessed both decision impulsivity (temporal discounting, TD) and time perception impulsivity (duration reproduction, DR) in 120 participants while they underwent electrocardiography in order to test whether cardiac signals were related to these two aspects of impulsivity. We found that over the entire period of task performance, individuals with higher heart rates had a tendency toward lower discount rates, supporting previous research that has associated sympathetic responses with decreased impulsivity. We also found that low-frequency components of heart rate variability (HRV) were associated with a less accurate perception of time, suggesting that time perception may be modulated by ANS function. Overall, these findings constitute preliminary evidence that autonomic function plays an important role in both decision impulsivity and time perception.

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.

Abstract Interval timing and working memory are critical components of cognition that are supported by neural oscillations in prefrontal-striatal-hippocampal circuits. In this review, the properties of interval timing and working memory are explored in terms of behavioral, anatomical, pharmacological, and neurophysiological findings. We then describe the various neurobiological theories that have been developed to explain these cognitive processes - largely independent of each other. Following this, a coupled excitatory - inhibitory oscillation (EIO) model of temporal processing is proposed to address the shared oscillatory properties of interval timing and working memory. Using this integrative approach, we describe a hybrid model explaining how interval timing and working memory can originate from the same oscillatory processes, but differ in terms of which dimension of the neural oscillation is utilized for the extraction of item, temporal order, and duration information. This extension of the striatal beat-frequency (SBF) model of interval timing (Matell and Meck, 2000, 2004) is based on prefrontal-striatal-hippocampal circuit dynamics and has direct relevance to the pathophysiological distortions observed in time perception and working memory in a variety of psychiatric and neurological conditions. Copyright 2014 Elsevier Ltd. All rights reserved.

Abstract The hypotheses that memories are ordered according to time and that contiguity is central to learning have recently reemerged in the human memory literature. This article reviews some of the key empirical findings behind this revival and some of the evidence against it, and finds the evidence for temporal organization unconvincing. A central problem is that, as many memory experiments are done, they have a prospective, as well as a retrospective, component. That is, if subjects can anticipate how they will be tested, they encode the to-be-remembered material in a way that they believe will facilitate performance on the anticipated test. Experiments that avoid this confounding factor have shown little or no evidence of organization by contiguity.

Abstract Two general frameworks have been articulated to describe how the passage of time is perceived. One emphasizes that the judgment of the duration of a stimulus depends on the operation of dedicated neural mechanisms specialized for representing the temporal relationships between events. Alternatively, the representation of duration could be ubiquitous, arising from the intrinsic dynamics of nondedicated neural mechanisms. In such models, duration might be encoded directly through the amount of activation of sensory processes or as spatial patterns of activity in a network of neurons. Although intrinsic models are neurally plausible, we highlight several issues that must be addressed before we dispense with models of duration perception that are based on dedicated processes.

Abstract Many people believe that life appears to speed up as they become older. However, age differences are only found studies in which participants compare recent with remote time passage. They are not found in studies in which younger participants impressions of recent time passage are compared to older participants impressions of recent time passage. Approaching the phenomenon as a memory issue allows for the discrepancy between these findings. In this study, two memory accounts for the phenomenon were examined. Whereas the results of the first experiment did not support the account that attributes the phenomenon to the difficulty with which events are retrieved from different lifetime periods, the results of the second experiment supported the account that attributes the phenomenon to the perceived time pressure in different lifetime periods. People are able to recall many recent instances in which they were very busy, had to rush, and did not have time to complete things, but these mundane and everyday events are often forgotten from more remote lifetime periods. People who have the impression that they are currently experiencing more time pressure than they were experiencing in the past will have the feeling that time has recently passed more quickly for them than time had in the past.

A number of psychophysical studies have shown that moving stimuli appear to last longer than static stimuli. Here, we report that the perceived duration for slow moving stimuli can be shorter than for static stimuli under specific circumstances. Observers were tested using natural movies presented at various speeds (0.0x = static, 0.25x = slow, or 1.9x = fast, relative to original speed) and indicated whether test duration was perceived as longer or shorter than comparison movies presented at their original speed. While fast movies were perceived as longer than slow and static movies (in accordance with previous studies), we found that slow movies were perceived as shorter (i.e., time compressed) compared to static images. Similar results were obtained for artificial stimuli consisting of drifting gratings. However, time compression for slow stimuli disappeared if comparison stimuli were replaced by a white static disk that removed repetitive exposures to moving stimuli. Results suggest that duration estimation is modulated by contextual effects induced by the specific diet or distribution of prior visual stimuli to which observers are exposed. A simple model, which includes a rapid recalibration of human time estimation via adaptation to preceding stimuli, succeeds in reproducing our experimental data.

Emotions are powerful drivers of distortions in time perception. Recent work continues to support arousal and attentional mechanisms of emotion-driven temporal distortions. A possible memory-related mechanism and various modulatory factors, such as age, gender, and psychopathology, have also been implicated in such distortions. Beyond the rich behavioral literature on this topic, neurobiological substrates associated with emotion-driven temporal distortions have begun to be identified and represent an important next step for research within this domain. The study of emotion-driven temporal distortions holds great promise for advancing our understanding of this perceptual phenomenon and how it may play a functional role in mediating changes in cognition, behavior, and emotion.

Abstract The hippocampus is critical to remembering the flow of events in distinct experiences and, in doing so, bridges temporal gaps between discontiguous events. Here, we report a robust hippocampal representation of sequence memories, highlighted by "time cells" that encode successive moments during an empty temporal gap between the key events, while also encoding location and ongoing behavior. Furthermore, just as most place cells "remap" when a salient spatial cue is altered, most time cells form qualitatively different representations ("retime") when the main temporal parameter is altered. Hippocampal neurons also differentially encode the key events and disambiguate different event sequences to compose unique, temporally organized representations of specific experiences. These findings suggest that hippocampal neural ensembles segment temporally organized memories much the same as they represent locations of important events in spatially defined environments. Copyright 2011 Elsevier Inc. All rights reserved.

The concept of the minimal self refers to the consciousness of oneself as an immediate subject of experience. According to recent studies, disturbances of the minimal self may be a core feature of schizophrenia. They are emphasized in classical psychiatry literature and in phenomenological work. Impaired minimal self experience may be defined as a distortion of one’s first-person experiential perspective as, for example, an ‘altered presence’ during which the sense of the experienced self (‘mineness’) is subtly affected, or ‘altered sense of demarcation’, i.e. a difficulty discriminating the self from the non-self. Little is known, however, about the cognitive basis of these disturbances. In fact, recent work indicates that disorders of the self are not correlated with cognitive impairments commonly found in schizophrenia such as working-memory and attention disorders. In addition, a major difficulty with exploring the minimal self experimentally lies in its definition as being non self-reflexive, and distinct from the verbalized, explicit awareness of an ‘I’. In this paper we shall discuss the possibility that disturbances of the minimal self observed in patients with schizophrenia are related to alterations in time processing. We shall review the literature on schizophrenia and time processing that lends support to this possibility. In particular we shall discuss the involvement of temporal integration windows on different time scales (implicit time processing) as well as duration perception disturbances (explicit time processing) in disorders of the minimal self. We argue that a better understanding of the relationship between time and the minimal self as well of issues of embodiment require research that looks more specifically at implicit time processing. Some methodological issues will be discussed.

Time is a universal psychological dimension, but time perception has often been studied and discussed in relative isolation. Increasingly, researchers are searching for unifying principles and integrated models that link time perception to other domains. In this review, we survey the links between temporal cognition and other psychological processes. Specifically, we describe how subjective duration is affected by non-temporal stimulus properties (perception), the allocation of processing resources (attention), and past experience with the stimulus (memory). We show that many of these connections instantiate a 'processing principle', according to which perceived time is positively related to perceptual vividity and the ease of information-extraction from the stimulus. This empirical generalization generates testable predictions and provides a starting-point for the development of integrated theoretical frameworks. Our intention is that, by outlining some of the links between temporal cognition and other domains, researchers in the field of timing and time perception will be encouraged to situate their work within broader theoretical frameworks, whilst researchers from other fields will be inspired to apply their insights, techniques, and theorizing to improve our understanding of the representation and judgment of time

One of the most widely used tasks for investigating psychological time, time reproduction, requires from participants the reproduction of the duration of a previously presented stimulus. Although prior studies have investigated the effects of different cognitive processes on time reproduction performance, no studies have looked into the effects of different reproduction methods on these performances. In the present study, participants were randomly assigned to one of three reproduction methods, which included (a) just pressing at the end of the interval, (b) pressing to start and stop the interval, and (c) maintaining continuous pressing during the interval. The study revealed that the three reproduction methods were not equivalent, with the method involving keypresses to start and stop the reproduction showing the highest accuracy, and the method of continuous press generating less variability.

Episodic or for the detailed events in our lives is critically dependent on structures of the medial temporal lobe (MTL). A fundamental component of episodic is for the temporal order of items within an episode. To understand the contribution of individual MTL structures to temporal-order , we recorded single-unit activity and local field potential from three MTL areas (hippocampus and entorhinal and perirhinal cortex) and visual area TE as performed a temporal-order task. Hippocampus provided incremental timing signals from one item presentation to the next, whereas perirhinal cortex signaled the conjunction of items and their relative temporal order. Thus, perirhinal cortex appeared to integrate timing information from hippocampus with item information from visual sensory area TE.

This study examined the role of medial temporal lobe structures in verbal estimation and production of time intervals. Left medial temporal lobe lesions produced deficits in both tasks, whereas right medial temporal lobe lesions only disturbed time production. Although both tasks require adequate use of chronometric units, they seem to be subserved by distinct cognitive processing and to depend on different neural substrates. Verbal estimation of intervals in retrospect seems to depend mainly on contextual memory, and production of intervals depends more specifically on the mental load devoted to time. These findings, documenting for the first time the role of each temporal lobe in duration estimation within the range of minutes, are discussed in light of memory-based and attentional models of time.

Temporal memory in 7-year-olds, 10-year-olds, and young adults (N = 78) was examined introducing a novel eye-movement paradigm. Participants learned object sequences and were tested under three conditions: temporal order, temporal context, and recognition. Age-related improvements in accuracy were found across conditions; accuracy in the temporal conditions was correlated with conventional time knowledge. Eye movements tracked the veridicality of temporal order memory in adults and 10-year-olds seconds before providing memory judgments, suggesting that these movements reflect implicit access to temporal information. Seven-year-olds overall did not show this eye-movement effect, but those who did were more accurate than those who did not. Results suggest that eye movements capture aspects of temporal memory development that precede overt decision processes ith implications for hippocampal development.

Abstract Anticipation of periodic events signalled by a time marker, or interval timing, has been explained by a separate pacemaker-counter clock. However, recent research has added support to an older idea: that memory strength can act as a clock. The way that memory strength decreases with time can be inferred from the properties of habituation, and the underlying process also provides a unified explanation for proportional timing, the Weber-law property and several other properties of interval timing.

Implicit preparation over time is a complex cognitive capacity important to optimize behavioral responses to a target occurring after a temporal interval, the so-called foreperiod (FP). If the FP occurs randomly and with the same a priori probability, shorter response times are usually observed with longer FPs than with shorter ones (FP effect). Moreover, responses are slower when the preceding FP was longer than the current one (sequential effects). It is still a matter of debate how different processes influence these temporal preparation phenomena. The present study used a dual-task procedure to understand how different processes, along the automatic-controlled continuum, may contribute to these temporal preparation phenomena. Dual-task demands were manipulated in two experiments using a subtraction task during the FP. This secondary task was administered in blocks (Experiment 1) or was embedded together with a baseline single-task in the same experimental session (Experiment 2). The results consistently showed that the size of the FP effect, but not that of sequential effects, is sensitive to dual-task manipulations. This functional dissociation unveils the multi-faceted nature of implicit temporal preparation: while the FP effect is due to a controlled, resource-consuming preparatory mechanism, a more automatic mechanism underlies sequential effects.

Abstract In this chapter I discuss so-called retrospective timing (what Ivry & Hazeltine, 1992, neatly label as “timing without a timer”) and passage of time judgements—judgements of how fast or slowly time seems to pass in some situations, as opposed to judgements of event duration.

Abstract A number of lines of evidence implicate dopamine in timing [Rammsayer, T. H. Neuropharmacological approaches to human timing. In S. Grondin (Ed.), Psychology of time (pp. 295-320). Bingley, UK: Emerald, 2008; Meck, W. H. Neuropharmacology of timing and time perception. Brain Research, Cognitive Brain Research, 3, 227-242, 1996]. Two human genetic polymorphisms are known to modulate dopaminergic activity. DRD2/ANKK1-Taq1a is a D(2) receptor polymorphism associated with decreased D(2) density in the striatum [J nsson, E. G., Nothen, M. M., Grunhage, F., Farde, L., Nakashima, Y., Propping, P., et al. Polymorphisms in the dopamine D(2) receptor gene and their relationships to striatal dopamine receptor density of healthy volunteers. Molecular Psychiatry, 4, 290-296, 1999]; COMT Val158Met is a functional polymorphism associated with increased activity of the COMT enzyme such that catabolism of synaptic dopamine is greater in pFC [Meyer-Lindenberg, A., Kohn, P. D., Kolachana, B., Kippenhan, S., McInerney-Leo, A., Nussbaum, R., et al. Midbrain dopamine and prefrontal function in humans: Interaction and modulation by COMT genotype. Nature Neuroscience, 8, 594-596, 2005]. To investigate the role of dopamine in timing, we genotyped 65 individuals for DRD2/ANKK1-Taq1a, COMT Val158Met, and a third polymorphism, BDNF Val66Met, a functional polymorphism affecting the expression of brain-derived neurotrophic factor [Egan, M. F., Kojima, M., Callicott, J. H., Goldberg, T. E., Kolachana, B. S., Bertolino, A., et al. The BDNF val66met polymorphism affects activity-dependent secretion of BDNF and human memory and hippocampal function. Cell, 112, 257-269, 2003]. Subjects were tested on a temporal discrimination task with sub- and supra-second intervals (500- and 2000-msec standards) as well as a spontaneous motor tempo task. We found a double dissociation for temporal discrimination: the DRD2/ANKK1-Taq1a polymorphism (A1+ allele) was associated with significantly greater variability for the 500-msec duration only, whereas the COMT Val158Met polymorphism (Val/Val homozygotes) was associated with significantly greater variability for the 2000-msec duration only. No differences were detected for the BDNF Vall66Met variant. Additionally, the DRD2/ANKK1-Taq1a polymorphism was associated with a significantly slower preferred motor tempo. These data provide a potential biological basis for the distinctions between sub- and supra-second timing and suggest that BG are integral for the former whereas pFC is implicated in the latter.

Coull and Nobre (2008) suggested that tasks that employ temporal cues might be divided on the basis of whether these cues are explicitly or implicitly processed. Furthermore, they suggested that implicit timing preferentially engages the left cerebral hemisphere. We tested this hypothesis by conducting a quantitative meta-analysis of eleven neuroimaging studies of implicit timing using the activation-likelihood estimation (ALE) algorithm (Turkeltaub, Eden, Jones, & Zeffiro, 2002). Our analysis revealed a single but robust cluster of activation-likelihood in the left inferior parietal cortex (supramarginal gyrus). This result is in accord with the hypothesis that the left hemisphere subserves implicit timing mechanisms. Furthermore, in conjunction with a previously reported meta-analysis of explicit timing tasks, our data support the claim that implicit and explicit timing are supported by at least partially distinct neural structures.

Abstract A large number of competing models exist for how the brain creates a representation of time. However, several human and animal studies point to 'climbing neural activation' as a potential neural mechanism for the representation of duration. Neurophysiological recordings in animals have revealed how climbing neural activation that peaks at the end of a timed interval underlies the processing of duration, and, in humans, climbing neural activity in the insular cortex, which is associated with feeling states of the body and emotions, may be related to the cumulative representation of time.

Emotion modulates our time perception. So far, the relationship between emotion and time perception has been examined with visible emotional stimuli. The present study investigated whether invisible emotional stimuli affected time perception. Using continuous flash suppression, which is a kind of dynamic interocular masking, supra-threshold emotional pictures were masked or unmasked depending on whether the retinal position of continuous flashes on one eye was consistent with that of the pictures on the other eye. Observers were asked to reproduce the perceived duration of a frame stimulus that was concurrently presented with a masked or unmasked emotional picture. As a result, negative emotional stimuli elongated the perceived duration of the frame stimulus in comparison with positive and neutral emotional stimuli, regardless of the visibility of emotional pictures. These results suggest that negative emotion unconsciously accelerates an internal clock, altering time perception.

Most theorists propose that when a person is aware that a duration judgment must be made (prospective paradigm), experienced duration depends on attention to temporal information, which competes with attention to nontemporal information. When a person is not aware that a duration judgment must be made until later (retrospective paradigm), remembered duration depends on incidental memory for temporal information. In the present article we describe two experiments in which durations involved with high-level, executive-control functions were judged either prospectively or retrospectively. In one experiment, the executive function involved resolving syntactic ambiguity in reading. In another experiment, it involved controlling the switching between tasks. In both experiments, there was a unique cost to the operation of control high-level, executive functions which was manifested by prospective reproductions shortening a finding that supports an attentional model of prospective timing. In addition, activation of executive functions produced contextual changes that were encoded in memory and resulted in longer retrospective reproductions, a finding that supports a contextual-change model of retrospective timing. Thus, different cognitive processes underlie prospective and retrospective timing. Recent findings obtained by some brain researchers also support these conclusions.