Temporal decision making in simultaneous timing

The effect of magnitude in a simultaneous duration assessment task among children - a replication study

The "magnitude effect" refers to the phenomenon where stimuli of greater magnitude appear to last longer in duration. Previous studies have explored this effect among children using various duration assessment tasks, but the findings have been inconsistent. Moreover, no replication studies have been conducted on this topic among children thus far. The simultaneous duration assessment task, which is one method for investigating time perception, has been used only twice in children and produced the magnitude effect. Thus, we aimed to replicate these findings and validate them through an additional replicated study. For these aims, we recruited 45 Arab-speaking children aged 7-12 to participate in two studies. In Study 1, they were asked to perform a simultaneous duration assessment task, where they had to assess the illumination durations of lightbulbs with strong and weak intensities simultaneously. In Study 2, they were asked to perform a duration reproduction task, where they had to reproduce the durations of illumination of the same stimuli. Both studies found a magnitude effect pattern, where the children tended to report that the lightbulb with the stronger intensity was illuminated for a longer duration or had a strong tendency to not choose the lightbulb with the weaker intensity. These results are discussed in terms of possible explanations for the conflicting results found in previous literature, as well as their consistency with the pacemaker model's explanation for the effect.

Simultaneous time processing in children and adults: When attention predicts temporal interference effects

Children from 5 to 8 years of age, as well as adults, performed a temporal reproduction task in both a solo-timing condition and a multi-timing condition, with different durations presented simultaneously. In the multi-timing condition, all durations were processed because the participants did not know in advance which stimulus needed to be judged. In a first experiment, two or three durations were presented with a synchrony of their onset. In a second experiment, two durations were presented simultaneously with asynchrony of their offset, different lengths of the concurrent duration, and different presentation orders. In addition, the participants' cognitive abilities in terms of selective attention, as well as short-term and working memory, were assessed with different neuropsychological tests. The results of both experiments showed that children and adults alike were able to process multiple durations simultaneously. However, the simultaneous presentation of different durations generated a temporal interference effect in children and adults, resulting in longer and more variable time estimates. This temporal interference effect was nevertheless higher in children due to their limited attention capacities. Therefore, a developmental improvement in the ability to process different durations simultaneously is related to the cognitive development of attention capacities.

When an Event Is Perceived Depends on Where We Attend

Does the moment when an event is perceived depends on where it is presented? To measure when participants perceived events, they were first familiarized with trial duration, by watching the hand of a clock rotating. Then, the hand was removed, and stimuli were presented at a random time from the trial onset. Participants indicated the location where the hand would have been when the stimulus was presented. The stimuli's eccentricity, the appearance, and location of the spatial features of the clock were varied. The targets were reported earlier if they were presented in spatial proximity to the clock outline, even when it was not presented during the trial. The effect was replicated with stimuli presented at the same distance from fixation but at different distances from the spatial features. In summary, the time of an event is perceived earlier if it is presented near attended features in the visual scene.

Capacity limit of simultaneous temporal processing: how many concurrent 'clocks' in vision?

A fundamental ability for humans is to monitor and process multiple temporal events that occur at different spatial locations simultaneously. A great number of studies have demonstrated simultaneous temporal processing (STP) in human and animal participants, i.e., multiple 'clocks' rather than a single 'clock'. However, to date, we still have no knowledge about the exact limitation of the STP in vision. Here we provide the first experimental measurement to this critical parameter in human vision by using two novel and complementary paradigms. The first paradigm combines merits of a temporal oddball-detection task and a capacity measurement widely used in the studies of visual working memory to quantify the capacity of STP (CSTP). The second paradigm uses a two-interval temporal comparison task with various encoded spatial locations involved in the standard temporal intervals to rule out an alternative, 'object individuation'-based, account of CSTP, which is measured by the first paradigm. Our results of both paradigms indicate consistently that the capacity limit of simultaneous temporal processing in vision is around 3 to 4 spatial locations. Moreover, the binding of the 'local clock' and its specific location is undermined by bottom-up competition of spatial attention, indicating that the time-space binding is resource-consuming. Our finding that the capacity of STP is not constrained by the capacity of visual working memory (VWM) supports the idea that the representations of STP are likely stored and operated in units different from those of VWM. A second paradigm confirms further that the limited number of location-bound 'local clocks' are activated and maintained during a time window of several hundreds milliseconds.