The aim of this study was to identify the age at which parameters of timing performance in a temporal bisection task converge on an adult-like stable level. Participants in the three- to 20-year-old range were tested using a temporal bisection task with sub-second and supra-second durations. The data were divided into two samples. In the first sample, all participants were integrated into the analysis regardless of their success. In the second sample, only performers were inserted. The point of subjective equality (PSE) and the Weber Ratio (WR) were analyzed for each participant in each sample. By fitting a mathematical model to these parameters as a function of age, we showed a large inter-individual variability in the PSE, such that it does not stabilize with increasing age, i.e., during the significant period of development. Interestingly, time sensitivity (WR) shows a similar pattern through the two samples as adult-like performance appeared at an earlier age for short than for long durations. For the first sample, the modeling of WR data suggests that the children reached an adult-like time sensitivity at the age of six years for the short durations and 8½ years for the long durations. For the second sample, the developmental curve was stable at about the same age for the long duration (seven years), and at earlier age for the short durations, i.e., before three years.
To anticipate other people’s behavioral intentions and respond to them at the right moment is crucial for efficient social interaction. In the present study, we thus investigated how adults synchronize with emotional facial expressions. The participants had to synchronize their taps with a rhythmical sequence of faces and then continue tapping at the same rhythm without faces. Three inter-stimulus intervals (500, 700, and 900 ms) and six different facial expressions (disgust, neutrality, sadness, joy, anger, and fear) were tested. In the synchronization phase, no difference was observed between the different facial expressions, suggesting that the participants tap in synchrony with external rhythms in the presence of stimuli whatever their emotional characteristics. However, in the continuation phase, an emotion effect emerged, with the individual rhythms being faster for the facial expressions of fear and, to a lesser extent, anger than for the other facial expressions. The motor rhythms were also longer and more variable for the disgusted faces. These findings suggest that the internal clock mechanism underlying the timing of rhythms is accelerated in response to the high-arousal emotions of fear and anger.
Temporal memory is formed from processes encoding and consolidating durations in memory. These processes can be enhanced in acute stressful contexts, which increase the arousal level, typical of the alert phase of the General Adaptation Syndrome of stress. However, prolonged stressful experiences (chronic stress) can cause damage to the storage of duration in memory. This study investigated the effects of psychological and physiological stress on the temporal memory of 50 nurses working in an emergency situation. They performed a temporal generalization task with a retention delay of 24 hours between the learning of a standard duration (4 s) and testing. Their blood was collected to examine circulating inflammatory markers related to stress. Their feeling of stress was also examined with two self-reported questionnaires, the Job Stress Scale (JSS) and the Perceived Stress Scale (PSS). The results show that temporal judgment is more variable when participants have high exposure to occupational stress (JSS). A quadratic relationship was also observed between the accuracy of time judgment and the level of perceived stress. Indeed, the proportion of accurate responses increased until a certain threshold of perceived stress, and then decreased. The results also showed a significant quadratic relationship between nitric oxide and the proportion of accurate responses. A low stress level is positively related to improving memory for a time, consistent with the reaction triggered in the alarm stage of the General Adaptation Syndrome of stress. However, above a certain level of stress, psychological and physiological stress damages temporal memory.
The past few decades have seen an explosion in studies exploring the effects of emotion on time judgments. The aim of this review is to describe the results of these studies and to look at how they try to explain the time distortions produced by emotion. We begin by examining the findings on time judgments in affective disorders, which allow us to make a clear distinction between the feelings of time distortion that originate from introspection onto subjective personal experience, and the effects of emotion on the basic mechanisms involved in time perception. We then report the results of behavioral studies that have tested the effects of emotions on time perceptions and the temporal processing of different emotional stimuli (e.g. facial expressions, affective pictures or sounds). Finally, we describe our own studies of the embodiment of timing. Overall, the different results on time and emotion suggest that temporal distortions are an indicator of how our brain and body adapt to the dynamic structure of our environment.