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The aim of this study was to compare the effect on interval discrimination of the presentation of disgusting mutilation images and the presentation of faces expressing disgust. In Experiments 1 and 2, participants had to say whether the second of two images was presented for a shorter or a longer duration than the first (intervals = 400 ms vs. 482 ms). Although the overall probability of responding “long” was not exactly the same in these two experiments, participants reported that duration was longer more often when disgusting mutilation images were presented than when neutral or disgusted faces were presented. In Experiment 3, in which a single-stimulus method was employed, mutilation images were once again reported to be presented for a longer duration than neutral or disgusted faces. The investigation also reveals that discrimination levels are not higher when mutilation images are presented. It is argued that the effect of mutilation images on perceived duration is not due to attention; it is rather attributed to the increased arousal caused by these images. -- Keywords : Temporal processing, Emotion, Time perception.

One factor influencing the perceived duration of a brief interval is the length of the period preceding it, namely the foreperiod (FP). When multiple FPs are varied randomly within a testing session, longer FPs result in longer perceived duration. The purpose of this study was to identify what characteristics modulate this effect. In a task where participants were asked to categorize the duration of target intervals with respect to a 100-ms standard, the FPs were distributed over a 150-, 300-, or 900-ms range with the midpoint (1000 ms) of these distributions being kept constant. The results indicate that the effect of the length of variable FPs on perceived duration was much stronger in the 900-ms range condition. More specifically, this effect is due to the differences between the shortest FPs. The results also reveal that, overall, there are more short responses in the 300-ms condition than in the other range conditions. Moreover, the data reveal that the narrower the distribution, the better the discrimination. One interpretation of the main result (range effect) is that a wider distribution leads to an increased prior uncertainty towards the foreperiod length.

The aim of the present study was to investigate sex-related variations in the perception of the duration of emotional stimuli (human faces). Twenty male and 20 female participants estimated the duration of angry, ashamed and neutral faces marking 0.4 to 1.6 s intervals. Female faces were used in one session, and male faces in the other. Compared to the angry faces condition, intervals were underestimated when ashamed faces were shown. However, the intervals in neither conditions were significantly overestimated or underestimated compared to the neutral condition. Even more critical is the fact that there was an underestimation by male participants of the duration of male faces compared to female faces; and female participants overestimated the duration in the anger condition, compared with the shame condition, only when male faces were presented. Moreover, the emotional effects on the participants’ performance were correlated to inter-individual differences in empathic abilities. The findings are discussed in terms of sex differences, of social context, and of how attention is solicited and arousal generated by emotions.

Some data in the time perception literature have indicated that Weber’s law for time does not hold: The Weber fraction gets higher with longer intervals. It is posited that this increase may reflect a fundamental information-processing limitation. If that is true, counting at a pace at which the intervals between counts remain within this capacity limitation should be more accurate than counting with intervals exceeding this capacity. In a task in which participants had to count up to a target number for a series of trials, the variability of the durations covered for reaching the target was higher when the intercount interval lasted 1,600 ms than when it lasted 800 ms. This finding provides evidence pointing toward the existence of a fundamental temporal limitation for processing information efficiently., Keywords Time perception . Counting

The aim of this study was to determine if the passage of time changes the memory of the duration of joyful or sad events. Participants were asked to look at a series of brief videos lasting 15¿minutes and to estimate retrospectively and verbally (with chronometric units) the duration of this 15-minute period. There were two independent variables: the emotion conditions (joy, sadness and neutral) and the recall conditions (immediately after the presentation of videos, 1¿week later or 1¿month later). The results show that the estimated time is largely overestimated in the 1-week and 1-month condition but not when the recall is immediate. This effect applies to each emotional condition, but there was no significant difference between the emotion conditions. The effect of emotion on the estimation of long intervals judged retrospectively seems minimal in comparison with the cognitive effect associated with the passage of time.

We investigated the discrimination of two neighboring intra- or inter-modal empty time intervals marked by three successive stimuli. Each of the three markers was a flash (visual—V) or a sound (auditory—A). The first and last markers were of the same modality, while the second one was either A or V, resulting in four conditions: VVV, VAV, AVA and AAA. Participants judged whether the second interval, whose duration was systematically varied, was shorter or longer than the 500-ms first interval. Compared with VVV and AAA, discrimination was impaired with VAV, but not so much with AVA (in Experiment 1). Whereas VAV and AVA consisted of the same set of single intermodal intervals (VA and AV), discrimination was impaired in the VAV compared to the AVA condition. This difference between VAV and AVA could not be attributed to the participants' strategy to perform the discrimination task, e.g., ignoring the standard interval or replacing the visual stimuli with sounds in their mind (in Experiment 2). These results are discussed in terms of sequential grouping according to sensory similarity., Keywords: Modality-specific timer Multisensory integration Inter-stimulus interval Discrimination Flash Sound

Participants are aware that they have to perform a temporal task in a prospective timing condition but not in a retrospective timing condition. In the present study, a direct comparison of temporal estimates under each paradigm is proposed via a strategy where each participant is restricted to only 1 response. Participants were assigned to either a prospective or retrospective testing condition and asked to reproduce and then estimate verbally 1 of 6 intervals lasting .5 to 16 s. The analyses based on Stevens’s power law were restricted to intervals lasting 2 to 16 s. With a verbal estimate method, the results indicate that the exponent is higher in retrospective than in prospective conditions (1.20 vs. 1.10 for females and 1.31 vs. 1.02 for males, respectively). For the interval reproduction task, the exponent based on Eisler’s (1975) model was slightly higher for males (1.13) than for females (1.08) in prospective timing, but slightly higher for females (1.10) than for males (1.04) in retrospective timing. The results based on inferential statistics and the 6 intervals reveal that, with the verbal estimate method, females make significantly larger relative verbal estimates than males and, at 16 s, intervals were judged as longer in the retrospective than in the prospective condition; with the reproduction method, the perceived duration is about the same in each paradigm and there is no significant sex effect. Overall, the data do not confirm that temporal intervals are perceived as longer in the prospective than in the retrospective conditions.

Some data in the time perception literature have indicated that Weber’s law for time does not hold: The Weber fraction gets higher with longer intervals. It is posited that this increase may reflect a fundamental information-processing limitation. If that is true, counting at a pace at which the intervals between counts remain within this capacity limitation should be more accurate than counting with intervals exceeding this capacity. In a task in which participants had to count up to a target number for a series of trials, the variability of the durations covered for reaching the target was higher when the intercount interval lasted 1,600 ms than when it lasted 800 ms. This finding provides evidence pointing toward the existence of a fundamental temporal limitation for processing information efficiently, Keywords Time perception . Counting

The aim of this study was to determine if the passage of time changes the memory of the duration of joyful or sad events. Participants were asked to look at a series of brief videos lasting 15¿minutes and to estimate retrospectively and verbally (with chronometric units) the duration of this 15-minute period. There were two independent variables: the emotion conditions (joy, sadness and neutral) and the recall conditions (immediately after the presentation of videos, 1¿week later or 1¿month later). The results show that the estimated time is largely overestimated in the 1-week and 1-month condition but not when the recall is immediate. This effect applies to each emotional condition, but there was no significant difference between the emotion conditions. The effect of emotion on the estimation of long intervals judged retrospectively seems minimal in comparison with the cognitive effect associated with the passage of time.

We investigated the discrimination of two neighboring intra- or inter-modal empty time intervals marked by three successive stimuli. Each of the three markers was a flash (visual—V) or a sound (auditory—A). The first and last markers were of the same modality, while the second one was either A or V, resulting in four conditions: VVV, VAV, AVA and AAA. Participants judged whether the second interval, whose duration was systematically varied, was shorter or longer than the 500-ms first interval. Compared with VVV and AAA, discrimination was impaired with VAV, but not so much with AVA (in Experiment 1). Whereas VAV and AVA consisted of the same set of single intermodal intervals (VA and AV), discrimination was impaired in the VAV compared to the AVA condition. This difference between VAV and AVA could not be attributed to the participants' strategy to perform the discrimination task, e.g., ignoring the standard interval or replacing the visual stimuli with sounds in their mind (in Experiment 2). These results are discussed in terms of sequential grouping according to sensory similarity., Keywords: Modality-specific timer Multisensory integration Inter-stimulus interval Discrimination Flash Sound