The influence of social stress on time perception and psychophysiological reactivity

Exploring the interplay between addiction and time perception: A systematic review and meta-analysis

Prior studies have investigated the immediate impacts of substances on temporal perception, the impact of temporal outlook, and the consequences of modified temporal perception on addictive behaviors. These inquiries have provided valuable perspectives on the intricate associations between addiction and time perception, enriching the groundwork for forthcoming research and therapeutic strategies. This comprehensive review aims to further explore intricate correlation among diverse addictive substances-namely alcohol, cannabis, nicotine, opioids-and non-substance addictions such as internet gaming, elucidating their influence on temporal perception. Adhering to the PICOS method and adhering to PRISMA guidelines, we systematically reviewed and critically evaluated all existing research concerning temporal perception in individuals with substance and non-substance use disorders. Specifically, our analyses involved 31 pertinent articles encompassing six unique groups-alcohol, nicotine, cannabis, stimulants, opioids, and internet-related addictions-sourced from a pool of 551 papers. The findings revealed differences in time perception between addicts and control groups, as indicated by medium to large effect sizes (Hedge's g = 0.8, p < 0.001). However, the nature of these differences-whether they predominantly involve time overestimation or underestimation-is not yet definitively clear. This variability underscores the complexity of the relationship between addiction and temporal perception, paving the way for further research to unravel these intricate dynamics.

Towards a neurodevelopmental cognitive perspective of temporal processing

The ability to organize and memorize the unfolding of events over time is a fundamental feature of cognition, which develops concurrently with the maturation of the brain. Nonetheless, how temporal processing evolves across the lifetime as well as the links with the underlying neural substrates remains unclear. Here, we intend to retrace the main developmental stages of brain structure, function, and cognition linked to the emergence of timing abilities. This neurodevelopmental perspective aims to untangle the puzzling trajectory of temporal processing aspects across the lifetime, paving the way to novel neuropsychological assessments and cognitive rehabilitation strategies.

Altered temporal awareness during Covid-19 pandemic

Social isolation during the COVID-19 pandemic had profound effects on human well-being. A handful of studies have focused on how time perception was altered during the COVID-19 pandemic, while no study has tested whether temporal metacognition is also affected by the lockdown. We examined the impact of long-term social isolation during the COVID-19 pandemic on the ability to monitor errors in timing performance. We recruited 1232 participants from 12 countries during lockdown, 211 of which were retested "post-pandemic" for within-group comparisons. We also tested a new group of 331 participants during the "post-pandemic" period and compared their data to those of 1232 participants tested during the lockdown (between-group comparison). Participants produced a 3600 ms target interval and assessed the magnitude and direction of their time production error. Both within and between-group comparisons showed reduced metric error monitoring performance during the lockdown, even after controlling for government-imposed stringency indices. A higher level of reported social isolation also predicted reduced temporal error monitoring ability. Participants produced longer duration during lockdown compared to post-lockdown (again controlling for government stringency indices). We reason that these effects may be underlain by altered biological and behavioral rhythms during social isolation experienced during the COVID-19 pandemic. Understanding these effects is crucial for a more complete characterization of the cognitive consequences of long-term social isolation.

Anticipation of sexually arousing visual event leads to overestimation of elapsed time

Subjective estimates of duration are affected by emotional expectations about the future. For example, temporal intervals preceding a threatening event such as an electric shock are estimated as longer than intervals preceding a non-threatening event. However, it has not been unequivocally shown that such temporal overestimation occurs also when anticipating a similarly arousing but appealing event. In this study, we examined how anticipation of visual erotic material influenced perceived duration. Participants did a temporal bisection task, where they estimated durations of visual cues relative to previously learned short and long standard durations. The color of the to-be-timed visual cue signalled either a chance of seeing a preferred erotic picture at the end of the interval or certainty of seeing a neutral grey bar instead. The results showed that anticipating an appealing event increased the likelihood of estimating the cue duration as long as compared to the anticipation of a grey bar. Further analyses showed that this temporal overestimation effect was stronger for those who rated the anticipated erotic pictures as more sexually arousing. The results thus indicate that anticipation of appealing events has a similar dilating effect on perceived duration as does the anticipation of aversive events.

The perception and passage of time during public speaking

Several studies have shown that anxious individuals experience a slower passage of time under threat conditioning. Anxiety-evoking situations have also been proposed to elevate arousal levels, which, in turn, alter one's time percept. However, the effect of social stressors on time perception remains significantly neglected. The current research aimed to investigate the impact of anxiety levels on time estimation and passage of time judgments during public speaking in healthy adults. Participants were recruited from a pool of students that had to give a presentation as part of a university course or their teaching duties. Following the presentation, they were asked to make retrospective time estimations on the duration of the latter, as well as to provide passage of time judgments. Self-reported questionnaires related to affective states, public speaking anxiety, and performance were also administered. Analysis showed that higher levels of public speaking anxiety predicted temporal overestimation and slower "feel" duration and passage of time. Moreover, the relationship between public speaking anxiety and passage of time was mediated by participants' mood states, which remained significant after -indirectly- controlling for fear of evaluation. Overall, our observations suggest that anxiety levels during public presentation significantly predict altered perception and experience of time. The latter can be explained by the speaker's mood status. Identifying the mechanisms that modulate timing under psychological stressors could complement our understanding regarding their impact on educational and social settings, as well as set the ground towards the development of early intervention and prevention strategies for those who suffer from stress-related disorders.

Time perception in stimulant-dependent participants undergoing repetitive transcranial magnetic stimulation

BACKGROUND

The dopaminergic (DA) system is an important neural system for the modulation of time perception and the timing of motor actions. Dysregulation of the DA system is related to chronic use of stimulant drugs, which lead, among others, to executive dysfunctions. Little is known instead about the potential deficiencies in temporal processing of stimulant-dependent individuals. The present study aimed to investigate temporal processing using a time bisection task with different temporal intervals in chronic cocaine users undergoing repetitive transcranial magnetic stimulation (rTMS).

METHOD

Study 1: A time bisection task with short temporal intervals range (480/1920 ms) was administered to 18 cocaine use disorder (CocUD) patients and 20 healthy control before and after the intensive phase of rTMS treatment (5 days apart). Study 2: 22 CocUD participants and 23 control participants completed two temporal tasks (time bisection and time reproduction) with long temporal intervals range (1200/2640 ms) at baseline and immediately after the intensive phase of rTMS treatment.

RESULTS

Study 1: A shift in the psychometric function consistent with temporal overestimation in CocUD patients compared to controls was observed. However, no temporal impairment in CocUD patients at test session was found. Study 2: The analysis of temporal variability indices showed a significant difference between groups at baseline but not at Day 5 due to a significant difference between time points only in the CocUD group.

CONCLUSIONS

This study report a temporal overestimation in CocUD patients and a temporal variability reduction after an rTMS protocol in CocUD patients.

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 effects of hydrocortisone and yohimbine on human behavior in approach-avoidance conflicts

RATIONALE

Balancing approach of positive and avoidance of negative stimuli is essential when faced with approach-avoidance conflicts, e.g., situations with both positive and negative outcomes. This balance is disturbed in several mental disorders, e.g., excessive avoidance in anxiety disorders, and heightened approach in substance use disorders. Since stress is assumed to impact these disorders' etiology and maintenance, it seems crucial to understand how stress influences behavior in approach-avoidance conflicts. Indeed, some studies suggested altered approach-avoidance behavior under acute stress, but the mechanism underlying these effects is unknown.

OBJECTIVES

Investigate how the pharmacological manipulation of major stress mediators (cortisol and noradrenaline) influences task-based approach-avoidance conflict behavior in healthy individuals.

METHODS

Ninety-six participants (48 women, 48 men) received either 20mg hydrocortisone, 20mg yohimbine, both, or placebo before performing a task targeting foraging under predation in a fully crossed double-blind between-subject design. Moreover, we investigated effects of gender and endogenous testosterone and estradiol levels on approach-avoidance behavior.

RESULTS

While biological stress markers (cortisol concentration, alpha amylase activity) indicated successful pharmacological manipulation, behavior in approach-avoidance conflicts was not affected as expected. Although yohimbine administration affected risky foraging latency under predation, we found no main effect of hydrocortisone or their interaction on behavior. In contrast, we found gender differences for almost all behavioral outcome measures, which might be explained by differences in endogenous testosterone levels.

CONCLUSIONS

The investigated major stress mediators were not sufficient to imitate previously shown stress effects on approach-avoidance conflict behavior. We discuss potential reasons for our findings and implications for future research.

Travel scenario workshops for geographical accessibility modeling of health services: A transdisciplinary evaluation study

Introduction

Limited geographical access to quality Emergency Obstetric and Newborn Care (EmONC) is a major driver of high maternal mortality. Geographic access to EmONC facilities is identified by the global community as a critical issue for reducing maternal mortality and is proposed as a global indicator by the Ending Preventable Maternal Mortality (EPMM) initiative. Geographic accessibility models can provide insight into the population that lacks adequate access and on the optimal distribution of facilities and resources. Travel scenarios (i.e., modes and speed of transport) used to compute geographical access to healthcare are a key input to these models and should approximate reality as much as possible. This study explores strategies to optimize and harmonize knowledge elicitation practices for developing travel scenarios.

Methods

Knowledge elicitation practices for travel scenario workshops (TSW) were studied in 14 African and South-Asian countries where the United Nations Population Fund supported ministries of health and governments in strengthening networks of EmONC facilities. This was done through a mixed methods evaluation study following a transdisciplinary approach, applying the four phases of the Interactive Learning and Action methodology: exploration, in-depth, integration, and prioritization and action planning. Data was collected in November 2020-June 2021 and involved scoping activities, stakeholder identification, semi-structured interviews (N = 9), an evaluation survey (N = 31), and two co-creating focus group discussions (N = 8).

Results

Estimating realistic travel speeds and limited time for the workshop were considered as the largest barriers. The identified opportunities were inclusively prioritized, whereby preparation; a favorable composition of attendees; validation practices; and evaluation were anticipated to be the most promising improvement strategies, explaining their central place on the co-developed initial standard operating procedure (SOP) for future TSWs. Mostly extensive preparation-both on the side of the organization and the attendees-was anticipated to address nearly all of the identified TSW challenges.

Conclusion

This study showed that the different identified stakeholders had contradicting, complementing and overlapping ideas about strategies to optimize and harmonize TSWs. Yet, an initial SOP was inclusively developed, emphasizing practices for before, during and after each TSW. This SOP is not only relevant in the context of the UNFPA EmONC development approach, but also for monitoring the newly launched EPMM indicator and even in the broader field of geographic accessibility modeling.

Stress effects on the top-down control of visuospatial attention: Evidence from cue-dependent alpha oscillations

Stress is assumed to inhibit the top-down control of attention and to facilitate bottom-up processing. Evidence from human experiments, however, remains scarce. Previous studies have addressed how stress affects the interplay of bottom-up and top-down mechanisms of attention. A key open question is in how far such effects can actually be attributed to a stress-induced modulation of top-down attention control. We sought to isolate top-down from bottom-up effects by assessing stress effects on anticipatory changes in alpha oscillations that precede stimulus processing. Participants performed in a cued target detection task in which a cue prompted them to covertly shift their attention to left or right screen positions, 20 min after being exposed to the bilateral feet cold pressor test or a warm water control procedure. The stressor led to a substantial increase in cortisol, peaking 20 min post stressor, along with rises in heart rate, blood pressure, and subjective ratings of stress and arousal. As expected, cued attention deployment led to higher alpha power over posterior electrodes contralateral versus ipsilateral to the attended hemifield during the cue-target interval. Importantly, this purely endogenous effect was potentiated by stress, however, significant differences were restricted to the middle of the cue-target interval and thus temporally separated from the appearance of the target. These results indicate that stress does not impair top-down attentional control per se but may introduce a qualitative change modulating the way attention is deployed to meet action goals.

Influence of Motor and Cognitive Tasks on Time Estimation

The passing of time can be precisely measured by using clocks, whereas humans’ estimation of temporal durations is influenced by many physical, cognitive and contextual factors, which distort our internal clock. Although it has been shown that temporal estimation accuracy is impaired by non-temporal tasks performed at the same time, no studies have investigated how concurrent cognitive and motor tasks interfere with time estimation. Moreover, most experiments only tested time intervals of a few seconds. In the present study, participants were asked to perform cognitive tasks of different difficulties (look, read, solve simple and hard mathematical operations) and estimate durations of up to two minutes, while walking or sitting. The results show that if observers pay attention only to time without performing any other mental task, they tend to overestimate the durations. Meanwhile, the more difficult the concurrent task, the more they tend to underestimate the time. These distortions are even more pronounced when observers are walking. Estimation biases and uncertainties change differently with durations depending on the task, consistent with a fixed relative uncertainty. Our findings show that cognitive and motor systems interact non-linearly and interfere with time perception processes, suggesting that they all compete for the same resources.

Student Reflections on Shared Trauma: One Year Later

In March of 2021, as the world marked the first anniversary since COVID-19 altered our reality, graduate social work students in Dr. Carol Tosone's Evidence-Based Trauma class at NYU considered the challenges of learning about trauma treatment while simultaneously living through a global trauma. Students reflected on their home lives, school experiences, field placements, mental health challenges, feelings of burnout, and the added complexities of racial disparities and injustices. Students also shared their coping mechanisms and hope for the future. This paper aims to provide insight into their varied experiences while relating their struggles and demonstrating their pathways toward resiliency.

Sympathetic involvement in time-constrained sequential foraging

Appraising sequential offers relative to an unknown future opportunity and a time cost requires an optimization policy that draws on a learned estimate of an environment’s richness. Converging evidence points to a learning asymmetry, whereby estimates of this richness update with a bias toward integrating positive information. We replicate this bias in a sequential foraging (prey selection) task and probe associated activation within the sympathetic branch of the autonomic system, using trial-by-trial measures of simultaneously recorded cardiac autonomic physiology. We reveal a unique adaptive role for the sympathetic branch in learning. It was specifically associated with adaptation to a deteriorating environment: it correlated with both the rate of negative information integration in belief estimates and downward changes in moment-to-moment environmental richness, and was predictive of optimal performance on the task. The findings are consistent with a framework whereby autonomic function supports the learning demands of prey selection.

Perception during use of force and the likelihood of firing upon an unarmed person

Stress can impact perception, especially during use-of-force. Research efforts can thus advance both theory and practice by examining how perception during use-of-force might drive behavior. The current study explored the relationship between perceptual judgments and performance during novel close-combat training. Analyses included perceptual judgments from close-combat assessments conducted pre-training and post-training that required realistic use-of-force decisions in addition to an artificially construed stress-inoculation event used as a training exercise. Participants demonstrated significant reductions in situational awareness while under direct fire, which correlated to increased physiological stress. The initial likelihood of firing upon an unarmed person predicted the perceptual shortcomings of later stress-inoculation training. Subsequently, likelihood of firing upon an unarmed person was reduced following the stress-inoculation training. These preliminary findings have several implications for low or zero-cost solutions that might help trainers identify individuals who are underprepared for field responsibilities.

Ventromedial Prefrontal Cortex Activity and Sympathetic Allostasis During Value-Based Ambivalence

Anxiety is characterized by low confidence in daily decisions, coupled with high levels of phenomenological stress. Ventromedial prefrontal cortex (vmPFC) plays an integral role in maladaptive anxious behaviors via decreased sensitivity to threatening vs. non-threatening stimuli (fear generalization). vmPFC is also a key node in approach-avoidance decision making requiring two-dimensional integration of rewards and costs. More recently, vmPFC has been implicated as a key cortical input to the sympathetic branch of the autonomic nervous system. However, little is known about the role of this brain region in mediating rapid stress responses elicited by changes in confidence during decision making. We used an approach-avoidance task to examine the relationship between sympathetically mediated cardiac stress responses, vmPFC activity and choice behavior over long and short time-scales. To do this, we collected concurrent fMRI, EKG and impedance cardiography recordings of sympathetic drive while participants made approach-avoidance decisions about monetary rewards paired with painful electric shock stimuli. We observe first that increased sympathetic drive (shorter pre-ejection period) in states lasting minutes are associated with choices involving reduced decision ambivalence. Thus, on this slow time scale, sympathetic drive serves as a proxy for "mobilization" whereby participants are more likely to show consistent value-action mapping. In parallel, imaging analyses reveal that on shorter time scales (estimated with a trial-to-trial GLM), increased vmPFC activity, particularly during low-ambivalence decisions, is associated with decreased sympathetic state. Our findings support a role of sympathetic drive in resolving decision ambivalence across long time horizons and suggest a potential role of vmPFC in modulating this response on a moment-to-moment basis.

Travel time and perinatal mortality after emergency caesarean sections: an evaluation of the 2-hour proximity indicator in Sierra Leone

INTRODUCTION

Longer travel times are associated with increased adverse maternal and perinatal outcomes. Geospatial modelling has been increasingly used to estimate geographic proximity in emergency obstetric care. In this study, we aimed to assess the correlation between modelled and patient-reported travel times and to evaluate its clinical relevance.

METHODS

Women who delivered by caesarean section in nine hospitals were followed up with home visits at 1 month and 1 year. Travel times between the location before the delivery and the facility where caesarean section was performed were estimated, based on two models (model I Ouma et al; model II Munoz et al). Patient-reported and modelled travel times were compared applying a univariable linear regression analysis, and the relation between travel time and perinatal mortality was assessed.

RESULTS

The median reported travel time was 60 min, compared with 13 and 34 min estimated by the two models, respectively. The 2-hour access threshold correlated with a patient-reported travel time of 5.7 hours for model I and 1.8 hours for model II. Longer travel times were associated with transport by boat and ambulance, visiting one or two facilities before reaching the final facility, lower education and poverty. Lower perinatal mortality was found both in the group with a reported travel time of 2 hours or less (193 vs 308 per 1000 births, p<0.001) and a modelled travel time of 2 hours or less (model I: 209 vs 344 per 1000 births, p=0.003; model II: 181 vs 319 per 1000 births, p<0.001).

CONCLUSION

The standard model, used to estimate geographical proximity, consistently underestimated the travel time. However, the conservative travel time model corresponded better to patient-reported travel times. The 2-hour threshold as determined by the Lancet Commission on Global Surgery, is clinically relevant with respect to reducing perinatal death, not a clear cut-off.

The Role of Future Time Perspective, Body Awareness, and Social Connectedness in the Relationship Between Self-efficacy and Resilience

Defined as the successful adaptation to dynamic environments, resilience is considered a cornerstone of mental health. However, with the underpinnings of resilience not yet fully understood, this manuscript tests the potential contribution of self-efficacy and embeddedness on resilience (explored through validated measures of future time perspective, body awareness, and social connectedness). The convenience sample of 18-to-77-year-old adults included 297 individuals, of which 36 were men and 171 were female. Participants completed online surveys composed of fifty-two questions in total, measuring self-efficacy, resilience, social connectedness, FTP, and body awareness. Resilience was positively related to self-efficacy, future time perspective, and social connectedness—but not to body awareness—and self-efficacy was positively associated with indices of embeddedness. Considering these correlations, and that only self-efficacy significantly predicted resilience, an exploratory model was proposed to test whether embeddedness directly predicted self-efficacy, and whether self-efficacy directly predicted resilience. Structural Equation Modelling suggested a good fit of this model, elucidating the interplay of psychological mechanisms underlying resilience. Thus, we identify potential variables of interest for clinical interventions aimed at increasing resilience and self-efficacy. Theoretical implications and future research are suggested based on these findings.

Slower perception of time in depressed and suicidal patients

Effective suicide prevention is hindered by a limited understanding of the natural progression and neurobiology of the suicidal process. Our objective was to characterize the duration of the suicidal process and its relation to possible determinants: time judgment and cognitive impulsivity. In four groups of adults of both sexes including recent suicide attempters (n = 57), suicidal ideators (n = 131), non-suicidal depressed controls (n = 51) and healthy controls (n = 48) we examined time estimation and production, impulsivity and other cognitive variables. Duration of the suicidal process was recorded in suicide attempters. The suicide process duration, suicide contemplation and action intervals, had a bimodal distribution, ∼40% of attempters took less than 5 min from decision to attempt. Time slowing correlated negatively with the suicidal action interval (time from the decision to kill oneself to suicide attempt) (p = .003). Individuals with suicide contemplation interval shorter than three hours showed increased time slowing, measured as shorter time production at 35 s (p = .011) and 43 s (p = .036). Delay discounting for rewards correlated with time estimation at 25 min (p = .02) and 90 s (p = .01). Time slowing correlated positively with suicidal ideation severity, independently of depression severity (p < .001). Perception of time slowing may influence both the intensity and the duration of the suicidal process. Time slowing may initially be triggered by intense psychological pain, then worsen the perception of inescapability in suicidal patients.

Similar time distortions under the effect of emotion for durations of several minutes and a few seconds

This study examined the effect of emotion on the judgment of durations of several minutes compared with that of durations of a few seconds. Three experiments were performed on the temporal judgment of emotional stimuli lasting from 2 s to 6 min (Experiment 1) or from 2 to 6 min (Experiment 2 and 3). These involved emotional sounds (Experiment 1 and 2) or virtual reality emotional films (Experiment 3). The results showed an increase in the lengthening of the perceived duration as the level of arousal and negative valence of the emotional stimuli increased, both for the long durations of several minutes and for the shorter durations. However, the magnitude of the time distortion tended to decrease as the length of the duration increased because the affects experienced by the participants lost their intensity over time. Nonetheless, when the exposure to emotional stimuli was limited and the stimuli were sufficiently arousing, as in Experiments 2 and 3, people overestimated time across durations ranging from seconds to minutes.

Time Passes Slowly When You Are Concealing Something

The item to be concealed elicits greater physiological arousal than other items. Since high physiological arousal causes an overestimation of time, the display duration of an item is expected to be perceived as longer when people intend to conceal it. After stealing and concealing one item, 36 university students were asked to judge the display duration of an item as shorter than, equal to, or longer than a memorised duration of 2 s. Pictures of three items including the stolen item were presented in the guilty condition, whereas pictures of three items that had not been stolen were presented in the innocent condition. The display of all items in the guilty condition was perceived as longer than in the innocent condition without difference between the concealed and other items. The intention to conceal increases tonic arousal reflected in a higher skin conductance level and leads to a non-specific temporal overestimation.

Quantitative meta-analysis of heart rate variability finds reduced parasympathetic cardiac tone in women compared to men during laboratory-based social stress

Heart rate variability (HRV) is the inter-beat interval variation between consecutive heartbeats and an autonomic reflection of emotional regulatory abilities to flexibly respond to challenges, such as psychosocial stress. Whereas there are known sex differences in stress-induced hormonal and emotional responses, we identified a gap in our understanding of sex-specific autonomic cardiac control during stress. Thus, we assessed HRV prior to, during and after administration of a public speech task in healthy participants (n = 929) according to sex. Our meta-analysis found that during stress, women had lower HRV than men, with an overall Hedges' g of 0.29 (p < 0.0001) and 0.29 (p = 0.0003) for fixed and random effects models, respectively. We did not find significant heterogeneity or evidence of publication bias. Analyses of additional timepoints showed no baseline difference and marginally lower HRV in women during anticipation and recovery. Findings of the present meta-analysis confirm sex differences in stress-induced hyperarousal and form a justification for implementation of mechanistic studies evaluating gonadal hormones, their potent metabolites and pro-inflammatory cytokines as mediators of this relationship.

The effect of increased parasympathetic activity on perceived duration

Theories of human temporal perception suggest that changes in physiological arousal distort the perceived duration of events. Behavioural manipulations of sympathetic nervous system (SNS) activity support this suggestion, however the effects of behavioural manipulations of parasympathetic (PSNS) activity on time perception are unclear. The current study examined the effect of a paced respiration exercise known to increase PSNS activity on sub-second duration estimates. Participants estimated the duration of negatively and neutrally valenced images following a period of normal and paced breathing. PSNS and SNS activity were indexed by high-frequency heart-rate variability and pre-ejection period respectively. Paced breathing increased PSNS activity and reduced the perceived duration of the negative and neutrally valenced stimuli relative to normal breathing. The results show that manipulations of PSNS activity can distort time in the absence of a change in SNS activity. They also suggest that activities which increase PSNS activity may be effective in reducing the perceived duration of short events.

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.

Gender Differences in the Effect of Facial Attractiveness on Perception of Time

Time perception plays a fundamental role in human social activities, and it can be influenced in social situations by various factors, including facial attractiveness. However, in the eyes of observers of different genders, the attractiveness of a face varies. The current study aimed to explore whether gender modulates the effect of facial attractiveness on time perception. To account for individual differences in esthetic standards, the critical stimuli presented to each participant were selected from an image pool based on the participant’s own attractiveness judgments. In Experiment 1, men and women performed a stimuli selection task followed by a temporal reproduction task to measure their time perception of faces of different attractiveness levels and gender. To control for the potential influence of task order, Experiment 2 flipped the order of the selection and temporal tasks. Taken together, the experiments showed that both men and women exhibited longer reproduced durations for attractive opposite-sex faces than for unattractive opposite-sex faces; conversely, in the same-sex face condition, women still exhibited longer reproduced durations for attractive faces than for unattractive faces, whereas the effect of facial attractiveness on time perception among men tended to be smaller or even fail to reach significance. These results suggest that gender differences play an important role in the effect of facial attractiveness on time perception.

Time distortion under threat: Sympathetic arousal predicts time distortion only in the context of negative, highly arousing stimuli

Theoretical models of time perception suggest a simple bottom-up relationship between physiological arousal and perceived duration. Increases in physiological arousal lengthen the perceived duration of events whereas decreases in physiological arousal reduce them. Whilst this relationship has been demonstrated for highly arousing negatively valenced stimuli, it has not been demonstrated for other classes of distorting stimuli (e.g. positively valenced or low arousal stimuli). The current study tested the effect of valence (positive and negative) and arousal level (high and low) on the relationship between physiological arousal and perceived duration. Sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) activity was measured during a verbal estimation task in which participants judged the duration of high and low arousal, positive, negative and neutrally valenced IAPS images. SNS and PSNS activity were indexed by measuring Pre-Ejection Period (PEP) and High Frequency Heart-rate Variability (HF-HRV) respectively. SNS reactivity was predicative of perceived duration, but only for high arousal negatively valenced stimuli, with decreases in PEP being associated with longer duration estimates. SNS and PSNS activity was not predictive of perceived duration for the low arousal negative stimuli or the low and high arousal positive stimuli. We therefore propose a new model suggesting that emotional distortions to time result from a combination of bottom-up (physiological arousal) and top-down (threat detection) factors.

Using Sensory Wearable Devices to Navigate the City: Effectiveness and User Experience in Older Pedestrians

Preserving older pedestrians’ navigation skills in urban environments is a challenge for maintaining their quality of life. However, the maps that are usually used by older pedestrians might be unsuitable to their specificities and the existing digital aids do not consider older people’s perceptual and cognitive declines or user experience. This study presents a rich description of the navigation experience of older pedestrians either with a visual (augmented reality glasses), auditory (bone conduction headphones), or a visual and haptic (smartwatch) wearable device adapted to age-related declines. These wearable devices are compared to the navigation aid older people usually use when navigating the city (their own digital or paper map). The study, with 18 participants, measured the navigation performance and captured detailed descriptions of the users’ experience using interviews. We highlight three main phenomena which impact the quality of the user experience with the four aids: (1) the shifts in attention over time, (2) the understanding of the situation over time, and (3) the emergence of affective and aesthetic feelings over time. These findings add a new understanding of the specificities of navigation experience by older people and are discussed in terms of design recommendations for navigation devices.