Effect on perceived duration and sensitivity to time when observing disgusted faces and disgusting mutilation pictures

The effect of modality and order presentation of emotional stimuli on time perception

Despite human accuracy in perceiving time, many factors can modulate the subjective experience of time. For example, it is widely reported that emotion can expand or shrink our perception of time and that temporal intervals are perceived as longer when marked by auditory stimuli than by visual stimuli. In the present study, we aimed at investigating whether the influence of emotion on time perception can be altered by the order in which emotional stimuli are presented and the sensory modality in which they are presented. Participants were asked to complete a time bisection task in which emotional stimuli were presented either acoustically or visually, and either before or after interval to be estimated. We observed a main effect of modality (longer perceived duration and lower variability in the auditory than in the visual modality) as well as a main effect of emotion (temporal overestimation for negative stimuli compared to neutral). Importantly, the effects of modality and emotion interacted with the order of presentation of the emotional stimuli. In the visual condition, when emotional stimuli were presented after the temporal intervals, participants overestimated time, but no differences between negative and neutral stimuli were observed when emotional stimuli were presented first. In the auditory condition, no significant effect of emotion on perceived duration was found. Results suggest that negative emotions affect our perception of durations acting at the decision-making stage rather than at the pacemaker one. No effect on time perception was observed for emotional auditory stimuli.

The Processing of Short Time Intervals: Some Critical Issues

Humans have the capability to make judgments about the relative duration of time intervals with accuracy (correct perceived duration) and precision (low variability). However, this capability has limitations, some of which are discussed in the present chapter. These limitations, either in terms of accuracy or precision, are obvious when there are changes in the physical characteristics of the stimuli used to mark the intervals to be judged. The characteristics are the structure (filled vs. empty) of the intervals and the sensory origin of the stimuli used to mark them. The variability of time estimates also depends on the use of single intervals by opposition to the use of sequences of intervals, and on the duration range under investigation. In addition to the effect caused by the physical characteristics of the stimuli, the perceived duration also relies on the way of presenting successive stimuli and on whether the intervals are marked by a single source or by different sources with distance (spatial effect) between them.

Psychophysiological stress influences temporal accuracy

Distortions of duration perception are often observed in response to highly arousing stimuli, but the exact mechanisms that evoke these variations are still under debate. Here, we investigate the effect of induced physiological arousal on time perception. Thirty-eight university students (22.89 ± 2.5; 28 females) were tested with spontaneous finger-tapping tasks and a time bisection task (with stimuli between 300 and 900 ms). Before the time bisection task, half of the participants (STRESS group) performed a stress-inducing task, i.e., the Paced Auditory Serial Addition Test (PASAT), whereas the other participants (CONTROL group) performed a control task, the Paced Auditory Number Reading Task (PANRAT). The PASAT induced a greater heart rate, but not electrodermal, increase, as well as a more unpleasant and arousing state compared to the PANRAT. Moreover, although the two groups presented a similar performance at the finger-tapping tasks, participants in the STRESS group showed better temporal performance at the time bisection task (i.e., lower constant error) than the controls. These results indicate that psychophysiological stress may alter the subsequent perception of time.

The role of valence, arousal, stimulus type, and temporal paradigm in the effect of emotion on time perception: A meta-analysis

Anecdotal experiences show that the human perception of time is subjective, and changes with one's emotional state. Over the past 25 years, increasing empirical evidence has demonstrated that emotions distort time perception and usually result in overestimation. Yet, some inconsistencies deserve clarification. Specifically, it remains controversial how valence (positive/negative), arousal (high/low), stimulus type (scenic picture/facial expression/word/sound), and temporal paradigm (reproduction/estimation/discrimination) modulate the effect of emotion on time perception. Thus, the current study aimed to conduct a meta-analysis to quantify evidence for these moderators. After searching the Web of Science, SpiScholar, and Google Scholar, 95 effect sizes from 31 empirical studies were calculated using Hedges'g. The included studies involved 3,776 participants. The results a highlighted significant moderating effect of valence, arousal, stimulus type, and temporal paradigm. Specifically, negative valence tends to result in overestimation relative to positive valence; the increasing arousal leads to increasing temporal dilating; scenic picture, facial picture, and sound are more effective in inducing distortions than word; the overestimation can be better observed by discrimination and estimation paradigms relative to reproduction paradigms, and estimation paradigm is likely to be the most effective. These results suggest that the effect of emotion on time perception is influenced by valence, arousal, stimulus type, and temporal paradigm. These mitigating factors should be considered by scientists when studying time perception.

Effect of food cues on time perception: influence of calories and diet control

The aim of this study was to investigate the influence on individuals' time perception of observing a range of foods differing in calorific content. In a first experiment, 92 adult participants performed a temporal bisection task with stimulus durations presented in the form of high- or low-calorie food pictures as well as matched non-food control pictures. In a second experiment, 102 participants performed a strict replication of Experiment 1, without the low-calorie pictures condition as it showed less pronounced effects. Across the two experiments, the data revealed common results. An overestimation of time was observed in relation to high-calorie food pictures when compared with non-food pictures (Experiment 2), and the effect was a function of participants' diet control (Experiments 1 & 2). Contrary to our hypothesis, the more the participants reported controlling their diet, the less they overestimated the time when presented with food stimuli. The participants who controlled their diet reported being less aroused by the high-calorie food pictures, allowing the assumption that the modulation in time overestimation relies on the arousal response generated by high-calorie food pictures.

Politically Biased Time Perception and Perspective

The main objective of this study was to determine if the estimation of time could be used to reveal an implicit political bias. The study also aimed at determining if a political bias is related to a specific temporal perspective or to other personality factors. The main demonstration is based on a bisection temporal task where the participants were asked to say if the duration of the presentation of a politician’s photo is short or long. There were three independent variables of interest: the location of politicians on the left (liberal) or right (conservative) on the political axis, the emotions expressed on a politician’s photo (joy, anger or neutral), and the political allegiances of the participants. Overall, compared to conditions with neutral faces or faces expressing joy, participants overestimated the duration of faces expressing anger. This effect, however, depends on the political allegiance of the participants. Compared to the neutral face condition, liberal participants overestimated the length of presentation of politicians’ faces in the joy and anger conditions. The results also showed that, compared to the condition in which photos of conservative politicians are presented, conservative participants underestimated the presentation duration of liberal politicians’ photos; such an influence of the orientation of presented politicians was not observed with liberal participants. The results also reveal that conservative participants differed from liberal participants on the future-oriented scale and on the past-positive-oriented scale of the Zimbardo Time Perspective Inventory (ZTPI). The study shows that time perception can be used to reveal a kind of implicit political bias.

Phrase Depicting Immoral Behavior Dilates Its Subjective Time Judgment

Intuitive moral emotions play a major role in forming our opinions and moral decisions. However, it is not yet known how we perceive the subjective time of moral-related information. In this study, we compared subjective durations of phrases depicting immoral, disgust, or neutral behaviors in a duration bisection task and found that phrases depicting immoral behavior were perceived as lasting longer than the neutral and disgusting phrases. By contrast, the subjective duration of the disgusting phrase, unlike the immoral phrase, was comparable to the neutral phrase. Moreover, the lengthening effect of the immoral phrase relative to the neutral phrase was significantly correlated to the anonymously prosocial tendency of the observer. Our findings suggest that immoral phrases induce embodied moral reaction, which alters emotional state and subsequently lengthens subjective time.

Do the young and the old perceive emotional intervals differently when shown on a younger or older face?

Many authors have analysed the effects of emotion recognition on time perception, showing that the more arousing the stimuli are the greater is the effect on duration perception. Visual stimuli, in particular faces, are the most recurrent stimuli employed in the literature. However, pictures in which emotional faces of older individuals have rarely been used, and when used, only young participants were tested. Hence, the present study is designed not only to analyse differences as regards duration perception in younger and older participants, but also to investigate the effects of neutral, happy, and angry facial expressions on younger and older participants when younger or older faces express those emotions. Results showed overestimation when emotional stimuli were presented. Interestingly, we observed temporal underestimation when the temporal intervals were marked by the image of younger participants and this was true in particular for older adults participants. Results are discussed in accordance with the internal clock model and in accordance with an inferential/reconstructive process occurring in memory and acting on temporal judgments.

Effect of glare illusion-induced perceptual brightness on temporal perception

Temporal perception and the ability to precisely ascertain time duration are central to essentially all behaviors. Since stimulus magnitude is assumed to be positively related to the perceived duration from the early days of experimental psychology, most studies so far have assessed this effect by presenting stimuli with relatively different intensities in physical quantity. However, it remains unclear how perceptual magnitude itself directly affects temporal perception. In this study (n = 21, n = 20), we conducted a two‐interval duration‐discrimination task adapting a glare illusion (a visual illusion that enhances perceived brightness without changing physical luminance) to investigate whether the temporal perception is also influenced by perceptual magnitude. Based on the mean difference in the point of subjective equality derived from a psychometric function and pupil diameter, we found that temporal perception is influenced by the illusory brightness of glare stimuli. Interestingly, the perceived duration of the apparently brighter stimuli (glare stimuli; larger pupillary light reflex) was shorter than that of control stimuli (halo stimuli; smaller pupillary light reflex) despite the stimuli remaining physically equiluminant, in contrast with the well‐known "magnitude effect." Furthermore, this temporal modulation did not occur when the physical luminance of the stimuli was manipulated to match the illusory‐induced magnitude. These results indicate that temporal processing depends on the confluence of both external and perceived subjective magnitude and even illusory brightness is sufficient to affect the sense of duration; which may be explained by the internal magnitude decrease of the glare stimuli due to pupillary constriction decreasing the light entering the eye.

Our findings suggest a new viewpoint on the positive relationship between temporal perception and stimulus magnitude, in demonstrating that temporal processing depends on the confluence of both external and perceived internal magnitude. We provide evidence that illusory brightness induced by the glare‐illusion also influences the perceived duration which may be explained by the size of the pupil.

Relaxing and stimulating effects of odors on time perception and their modulation by expectancy

Although several studies have reported relaxing and stimulating effects of odors on physiology and behavior, little is known about their underlying mechanisms. It has been proposed that participant expectancy could explain these activation effects. Since emotional stimuli are known to modulate time perception, here we used the temporal bisection task to determine whether odors have objective relaxing and stimulating effects by respectively slowing down or speeding up the internal clock and whether prior expectancy could alter these effects. In Experiment 1, 118 participants were presented either with a strawberry odor or an odorless blank. In Experiment 2, 132 participants were presented either with a lemon odor or an odorless blank. In both experiments, expectancy was manipulated using suggestion (verbal instructions). The stimulus was either described as relaxing or stimulating, or was not described. In the absence of prior suggestion, findings showed that, compared to participants presented with an odorless blank, participants presented with the strawberry odor underestimated sound durations (i.e., a relaxing effect) whereas participants presented with the lemon odor overestimated them (i.e., a stimulating effect). These results confirm that pleasant odors can have objective relaxing and stimulating effects by themselves, which are better explained by arousal-based mechanisms rather than attentional distraction. Furthermore, in both experiments, incongruent suggestions undid the effects of both odors without reversing them completely (i.e., strawberry did not become stimulating even if participants were told so). Both these bottom-up and top-down influences should be considered when investigating the emotional impact of odors on human behavior.

Pandemic, Quarantine, and Psychological Time

This article addresses the feeling of strangeness about the perception of time that many people with ordinary lifestyles experienced during the quarantine imposed to fight the presence of COVID-19. It describes different aspects of psychological time affected by the interruption of a normal routine and suggests some cognitive mechanisms, attention, and memory that might have been at play, leading to perceive time as being more or less long. The article also describes the critical role of anxiety and temporal uncertainty and how they may affect the functioning of an internal clock and reminds the reader that there are individual differences in time-related aspects of the personality that contribute to the variety of impressions about duration experienced during the quarantine.

Do I dislike what you dislike? Investigating the effect of disgust on time processing

Time perception can be distorted by emotional stimuli. The present study aims to investigate the effect of disgust on time perception in young adults. Here, we report two experiments in which a time bisection task was used with intervals lasting 400 ms (short standard) to 1600 ms (long standard). In Experiment 1, temporal intervals were marked by neutral images or images from food (rotten, joyful), and facial (disgust, happy) categories. In Experiment 2, disgust-eliciting and neutral stimuli belonging to seven different domains were used: faces, food, animals, body products, injury/infections, death and hygiene. Results showed temporal overestimations when, compared to neutral conditions, disgusted faces (Experiments 1 and 2) and disgusting death and hygiene stimuli (Experiment 2) were used, and a temporal underestimation when images of rotten food (Experiment 1) were used. Results are discussed in terms of arousal-based and attention-based processes and showed that the degree of the emotional component influences time perception.

Amygdala-prefrontal cortex connectivity increased during face discrimination but not time perception

Time sensitivity is affected by emotional stimuli such as fearful faces. The effect of threatening stimuli on time perception depends on numerous factors, including task type and duration range. We applied a two-interval forced-choice task using face stimuli to healthy volunteers to evaluate time perception and emotion interaction using functional magnetic resonance imaging. We conducted finite impulse response analysis to examine time series for the significantly activated brain areas and psycho-physical interaction to investigate the connectivity between selected regions. Time perception engaged a right-lateralised frontoparietal network, while a face discrimination task activated the amygdala and fusiform face area (FFA). No voxels were active with regard to the effect of expression (fearful versus neutral). In parallel with this, our behavioural results showed that attending to the fearful faces did not cause duration overestimation. Finally, connectivity of the amygdala and FFA to the middle frontal gyrus increased during the face processing condition compared to the timing task. Overall, our results suggest that the prefrontal-amygdala connectivity might be required for the emotional processing of facial stimuli. On the other hand, attentional load, task type and task difficulty are discussed as possible factors that influence the effects of emotion on time perception.

Increased temporal sensitivity for threat: A Bayesian generalized linear mixed modeling approach

People overestimate the duration of threat-related facial expressions, and this effect increases with self-reported fearfulness (Tipples in Emotion, 8, 127-131, 2008, Emotion, 11, 74-80, 2011). One explanation (Cheng, Tipples, Narayanan, & Meck in Timing and Time Perception, 4, 99-122, 2016) for this effect is that emotion increases the rate at which temporal information accumulates. Here I tested whether increased overestimation for threat-related facial expressions in high fearfulness generalizes to pictures of threatening animals. A further goal was to illustrate the use of Bayesian generalized linear mixed modeling (GLMM) to gain more accurate estimates of temporal performance, including estimates of temporal sensitivity. Participants (N = 53) completed a temporal bisection task in which they judged the presentation duration for pictures of threatening animals (poised to attack) and nonthreatening animals. People overestimated the duration of threatening animals, and the effect increased with self-reported fearfulness. In support of increased accumulation of pacemaker ticks due to threat, temporal sensitivity was higher for threat than for nonthreat images. Analyses indicated that temporal sensitivity effects may have been absent in previous research because of the method used to calculate the index of temporal sensitivity. The benefits of using Bayesian GLMM are highlighted, and researchers are encouraged to use this method as the first option for analyzing temporal bisection data.

The Effects of Same- and Other-Race Facial Expressions of Pain on Temporal Perception

Previous studies suggested that threatening stimuli lengthen subjective duration, while facial expressions of pain were found to produce a shortening effect on temporal perception in a recent study. Moreover, individuals' responses to others' pain were influenced by the individuals' relationship to a racial group. However, the effects of same- and other-race pained facial expressions on temporal perception, remain unknown. The aim of this present study was to identify the effect expressions of pain have on temporal perception and to explore whether this effect was modulated by the relationship to a racial group. In a temporal bisection task, Chinese participants were presented with pain or neutral facial expressions displayed by Caucasian (other-race) or Chinese (same-race) models in a 400-1600 ms or 200-800 ms condition. Expressions of pain were rated as more arousing, negative and disagreeable, than neutral facial expressions. These scores were not significantly different between same- and other-race facial expressions. Based on the results of the temporal bisection task, both same- and other-race pained facial expressions lengthened the perceived duration in the 400-1600 ms condition, but only same-race pained facial expressions produced this effect in the 200-800 ms condition. We postulate that the existence of a short-lived effect of pained facial expressions on lengthening temporal perception caused by arousal and attention, occurs at an earlier time point for same-race pained facial expressions than for other-race pained facial expressions.

Temporal Processing of Joyful and Disgusting Food Pictures by Women With an Eating Disorder

The present study used the presentation of food pictures and judgements about their duration to assess the emotions elicited by food in women suffering from an eating disorder (ED). Twenty-three women diagnosed with an ED, namely anorexia (AN) or bulimia nervosa (BN), and 23 healthy controls (HC) completed a temporal bisection task and a duration discrimination task. Intervals were marked with emotionally pre-rated pictures of joyful and disgusting food, and pictures of neutral objects. The results showed that, in the bisection task, AN women overestimated the duration of food pictures in comparison to neutral ones. Also, compared to participants with BN, they perceived the duration of joyful food pictures as longer, and tended to overestimate the duration of the disgusting ones. These effects on perceived duration suggest that AN women experienced an intense reaction of fear when they were confronted to food pictures. More precisely, by having elevated the arousal level and activated the defensive system, food pictures seemed to have speeded up the rhythm of the AN participants’ internal clock, which led to an overestimation of images’ duration. In addition, the results revealed that, in both tasks, ED women presented a lower temporal sensitivity than HC, which was related to their ED symptomatology (i.e., BMI, restraint and concern) and, particularly, to their weaker cognitive abilities in terms of attention, processing speed and working memory. Considered all together, the findings of the present experiment highlight the role of fear and anxiety in the manifestations of AN and point out the importance of considering non-temporal factors in the interpretation of time perception performance.

Color and time perception: Evidence for temporal overestimation of blue stimuli

The perceived duration of a visual stimulus depends on various features, such as its size, shape, and movement. Potential effects of stimulus color have not been investigated in sufficient detail yet, but the well-known effects of arousal on time perception suggest that arousing hues, such as red, might induce an overestimation of duration. By means of a two-interval duration discrimination task in the sub-second range, we investigated whether participants overestimate the duration of red stimuli in comparison to blue stimuli, while controlling for differences in brightness (individual adjustments by means of flicker photometry) and saturation (colorimetric adjustment in terms of the CIELAB color space). Surprisingly, our results show an overestimation of the duration of blue compared to red stimuli (indicated by a shift of the point of subjective equality), even though the red stimuli were rated as being more arousing. The precision (variability) of duration judgments, i.e., the duration difference limen, did not differ between red and blue stimuli, questioning an explanation in terms of attentional processes.

Effects of happy and sad facial expressions on the perception of time in Parkinson's disease patients with mild cognitive impairment

INTRODUCTION

Parkinson's disease (PD) is a movement disorder caused by deterioration of the dopaminergic system. Previous studies have demonstrated temporal as well as emotional facial recognition impairment in PD patients. Moreover, it has been demonstrated that emotional facial expressions alter temporal judgments. In the present study, we investigate the magnitude of temporal distortions caused by the presentation of emotional facial expressions (happiness, sadness, and neutral) in PD patients with mild cognitive impairment (PD-MCI) and controls.

METHOD

Seventeen older adults with PD-MCI and 22 healthy older adults took part in the present study. Participants were tested with a time bisection task with standard intervals lasting 400 ms and 1600 ms. Moreover, a complete neuropsychological evaluation was conducted to characterize the sample.

RESULTS

Differences between groups were observed indicating a general underestimation of time in PD-MCI patients. Temporal impairments in PD-MCI patients seem to be caused mainly by a dysfunction at the level of reference memory. The effect of emotional facial expressions on time perception was evident in both PD patients and controls, with an overestimation of perceived duration when happiness was presented and an underestimation when sadness was presented.

CONCLUSION

Overall, our results indicate that reduced cognitive abilities might be responsible for the lower temporal ability observed in PD-MCI patients. Moreover, similar effects of emotional stimuli were observed in both PD-MCI patients and controls.

Women Overestimate Temporal Duration: Evidence from Chinese Emotional Words

Numerous studies have proven the effect of emotion on temporal perception, using various emotional stimuli. However, research investigating this issue from the lexico-semantic perspective and gender difference remains scarce. In this study, participants were presented with different types of emotional words designed in classic temporal bisection tasks. In Experiment 1 where the arousal level of emotional words was controlled, no pure effect of valence on temporal perception was found; however, we observed the overestimation of women relative to men. Furthermore, in Experiment 2, an orthogonal design of valence and arousal with neutral condition was employed to study the arousal-mechanism of temporal distortion effect and its difference between genders. The results showed that the gender difference observed in Experiment 1 was robust and was not influenced by valence and arousal. Taken together, our findings suggest a stable gender difference in the temporal perception of semantic stimuli, which might be related to some intrinsic properties of linguistic stimuli and sex differences in brain structure as well as physiological features. The automatic processing of time information was also discussed.

Initial and sustained brain responses to threat anticipation in blood-injection-injury phobia

Blood-injection-injury (BII) phobia differs from other subtypes of specific phobia in that it is associated with elevated disgust-sensitivity as well as specific autonomic and brain responses during processing of phobia-relevant stimuli. To what extent these features play a role already during threat anticipation is unclear. In the current fMRI experiment, 16 female BII phobics and 16 female healthy controls anticipated the presentation of phobia-specific and neutral pictures. On the behavioral level, anxiety dominated the anticipatory period in BII phobics relative to controls, while both anxiety and disgust were elevated during picture presentation. By applying two different models for the analysis of brain responses to anticipation of phobia-specific versus neutral stimuli, we found initial and sustained increases of activation in anterior cingulate cortex (ACC), insula, lateral and medial prefrontal cortex (PFC), thalamus and visual areas, as well as initial activation in the amygdala for BII phobics as compared to healthy controls. These results suggest that BII phobia is characterized by activation of a typical neural defense network during threat anticipation, with anxiety as the predominant emotion.

Perceived time slows during fleeting fun or fear

Previous psychophysical studies at durations greater than 1000 ms have confirmed the anecdotal reports of an increase in the perceived duration of both positively and negatively valenced emotive stimuli; however, the results of studies at durations less than 1000 ms have been inconsistent. This study further investigated the effect of valence on the perception of durations less than 1000 ms. We used both positively and negatively valenced stimuli in order to compare their effects on the distortion of duration, and we tested multiple data points within the sub-one-second range. We found an increase in the perceived duration of both positively and negatively valenced emotional stimuli at all data points. This is consistent with studies at durations longer than 1000 ms and also with models of temporal processing. We also confirmed that Weber fractions, within the range tested, followed the generalized form of Weber's law.

Effects of Emotional Facial Expression on Time Perception in Patients with Parkinson's Disease

Previous studies have demonstrated that emotional facial expressions alter temporal judgments. Moreover, while some studies conducted with Parkinson's disease (PD) patients suggest dysfunction in the recognition of emotional facial expression, others have shown a dysfunction in time perception. In the present study, we investigate the magnitude of temporal distortions caused by the presentation of emotional facial expressions (anger, shame, and neutral) in PD patients and controls. Twenty-five older adults with PD and 17 healthy older adults took part in the present study. PD patients were divided into two sub-groups, with and without mild cognitive impairment (MCI), based on their neuropsychological performance. Participants were tested with a time bisection task with standard intervals lasting 400 ms and 1600 ms. The effect of facial emotional stimuli on time perception was evident in all participants, yet the effect was greater for PD-MCI patients. Furthermore, PD-MCI patients were more likely to underestimate long and overestimate short temporal intervals than PD-non-MCI patients and controls. Temporal impairment in PD-MCI patients seem to be mainly caused by a memory dysfunction. (JINS, 2016, 22, 890-899).

Watching a real moving object expands tactile duration: the role of task-irrelevant action context for subjective time

Although it is well established that action contexts can expand the perceived durations of action-related events, whether action contexts also impact the subjective duration of events unrelated to the action remains an open issue. Here we examined how the automatic implicit reactions induced by viewing task-irrelevant, real moving objects influence tactile duration judgments. Participants were asked to make temporal bisection judgments of a tactile event while seeing a potentially catchable swinging ball. Approaching movement induced a tactile-duration overestimation relative to lateral movement and to a static baseline, and receding movement produced an expansion similar in duration to that from approaching movement. Interestingly, the effect of approaching movement on the subjective tactile duration was greatly reduced when participants held lightweight objects in their hands, relative to a hands-free condition, whereas no difference was obtained in the tactile-duration estimates between static hands-free and static hands-occupied conditions. The results indicate that duration perception is determined by internal bodily states as well as by sensory evidence.

Time perception in anxious and depressed patients: A comparison between time reproduction and time production tasks

Several studies reported temporal dysfunctions in anxious and depressed patients. In particular, compared to controls, anxious patients report that time is passing fast whereas depressed patients report that time passes slowly. However, in some studies, no differences between patients and controls are reported. Direct comparison between studies may be complex because of methodological differences, including the fact of conducting investigations with different temporal ranges. In the present study, we tested a group of anxious patients, a group of depressed patients, and a control group with two temporal tasks (time reproduction and time production) with the same temporal intervals (500, 1000 and 1500ms) to further investigate the presence and cause of patients' temporal dysfunctions. Results showed that, compared to controls, anxious patients under-reproduced temporal intervals and depressed patients over-produced temporal intervals. The results suggest that time dysfunction in anxious patients would be mainly due to an attentional dysfunction whereas temporal dysfunction in depressed patients would be mainly due to variations in the pulses' emission rate of the pacemaker.

Emotional modulation of interval timing and time perception

Like other senses, our perception of time is not veridical, but rather, is modulated by changes in environmental context. Anecdotal experiences suggest that emotions can be powerful modulators of time perception; nevertheless, the functional and neural mechanisms underlying emotion-induced temporal distortions remain unclear. Widely accepted pacemaker-accumulator models of time perception suggest that changes in arousal and attention have unique influences on temporal judgments and contribute to emotional distortions of time perception. However, such models conflict with current views of arousal and attention suggesting that current models of time perception do not adequately explain the variability in emotion-induced temporal distortions. Instead, findings provide support for a new perspective of emotion-induced temporal distortions that emphasizes both the unique and interactive influences of arousal and attention on time perception over time. Using this framework, we discuss plausible functional and neural mechanisms of emotion-induced temporal distortions and how these temporal distortions may have important implications for our understanding of how emotions modulate our perceptual experiences in service of adaptive responding to biologically relevant stimuli.

Recent advances in understanding emotion-driven temporal distortions

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.

The emotional body and time perception

We examined the effects of emotional bodily expressions on the perception of time. Participants were shown bodily expressions of fear, happiness and sadness in a temporal bisection task featuring different stimulus duration ranges. Stimulus durations were judged to be longer for bodily expressions of fear than for those of sadness, whereas no significant difference was observed between sad and happy postures. In addition, the magnitude of the lengthening effect of fearful versus sad postures increased with duration range. These results suggest that the perception of fearful bodily expressions increases the level of arousal which, in turn, speeds up the internal clock system underlying the representation of time. The effect of bodily expressions on time perception is thus consistent with findings for other highly arousing emotional stimuli, such as emotional facial expressions.

Interval discrimination across different duration ranges with a look at spatial compatibility and context effects

In the present study, a time discrimination task was used to investigate the effect of different contexts for intervals varying from 400 to 1600 ms. A potential time-space interaction was controlled, and participants used both manual responses (Experiments 1 and 2) and vocal responses (Experiment 3). Three ranges of durations were employed (short, middle and long), and within each range condition, three standard values were used (400, 700, and 1000 ms; 700, 1000, and 1300 ms; and 1000, 1300, and 1600 ms). Within each range, standard intervals were randomized (Experiments 1 and 3) or remained constant (Experiment 2) within a block of trials. Our results suggest that context influences time discrimination performances only when the temporal range under investigation is below 1300 ms and the temporal intervals varied within blocks. In the case of temporal intervals longer than 1300 ms, participants presented a tendency to respond “long” independently of the procedure used. Moreover, our results suggested that performances in a discrimination task are mainly influenced by the fact of varying standard durations within blocks, and not much by the time-space compatibility.

Temporal dysfunction in traumatic brain injury patients: primary or secondary impairment?

Adequate temporal abilities are required for most daily activities. Traumatic brain injury (TBI) patients often present with cognitive dysfunctions, but few studies have investigated temporal impairments associated with TBI. The aim of the present work is to review the existing literature on temporal abilities in TBI patients. Particular attention is given to the involvement of higher cognitive processes in temporal processing in order to determine if any temporal dysfunction observed in TBI patients is due to the disruption of an internal clock or to the dysfunction of general cognitive processes. The results showed that temporal dysfunctions in TBI patients are related to the deficits in cognitive functions involved in temporal processing rather than to a specific impairment of the internal clock. In fact, temporal dysfunctions are observed when the length of temporal intervals exceeds the working memory span or when the temporal tasks require high cognitive functions to be performed. The consistent higher temporal variability observed in TBI patients is a sign of impaired frontally mediated cognitive functions involved in time perception.