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When the duration of a pre-target interval probabilistically predicts the identity of the target, participants typically form time-based expectancies: they respond faster to frequent interval-target combinations than to infrequent ones. Yet, previous research investigating the cognitive time-processing mechanisms underlying time-based expectancy assessed time-based expectancy always in situations with a binary set of intervals (i.e. short vs. long). Here we aim to test whether time-based expectancy transfers to more complex settings with three different predictive time intervals (short, medium, long) in which each predicts one of three different target stimuli with 80% probability. In three experiments we varied how the medium interval was computed (arithmetic mean, geometric mean, or in between both). Our results showed that participants were able to learn the time-event contingencies for the short and the long as well as for the medium interval, and were, thus able to flexibly redirect their target expectancy two times during the course of a trial. The evidence concerning the impact of the manipulation of the medium intervals' absolute duration on time-based expectancy was, however, mixed, as time-based expectancy for the medium interval could only be observed in one of three reported experiments. In sum, the findings of the present study suggest a previously unknown cognitive flexibility underlying time-based expectancy and offer important theoretical implications, challenging future research on the timing mechanisms involved in time-based expectancy., (© 2021. The Author(s).)

The temporal predictability of upcoming events plays a crucial role in the adjustment of anticipatory cognitive control in multitasking. Previous research has demonstrated that task switching performance improved if tasks were validly predictable by a pre-target interval. Hence, far, the underlying cognitive processes of time-based task expectancy in task switching have not been clearly defined. The present study investigated whether the effect of time-based expectancy is due to expectancy of post-perceptual task components or rather due to facilitation of perceptual visual processing of the coloured task indicator. Participants performed two numeric judgment tasks (parity vs. magnitude), which were each indicated by two different colours. Each task was either more or less frequently preceded by one of two intervals (500 ms or 1500 ms). Tasks were indicated either by colours that were each more frequently (or in Exp. 1 also less frequently) paired with the interval or by colours that were equally frequent for each interval. Participants only responded faster when colour and task were predictable by time (expected colour), not when the task alone was predictable (neutral colour). Hence, our results speak in favour of perceptual time-based task indicator expectancy being the underlying cognitive mechanism of time-based expectancy in the task switching paradigm., (© 2021. The Author(s).)

Recent research has shown that humans are able to implicitly adapt to time-transition contingencies in a task-switching paradigm, indicated by better performance in trials where the task transition (switch vs. repetition) is validly predicted by the pre-target interval compared to trials with invalidly predicted transitions. As participants switched between only two different tasks, not only the transition, but also the specific task was predictable; at least indirectly when taking into account the temporally predicted transition in the current trial together with the task in the previous trial. In order to investigate if the time-based expectancy effect for transition in previous studies was due to a specific task preparation or due to an unspecific transition preparation, three different tasks were used in the present study. One of two possible pre-target intervals (500 and 1500 ms) predicted a task switch in the upcoming trial with 90 % probability, whereas the other interval predicted a task repetition with 90 % probability. Results revealed that participants were able to prepare both upcoming repetition as well as switch requirements based on predictive pre-target intervals. This means that humans seem to be able to prepare a task switch in a rather unspecific manner, most likely by inhibiting the task just performed in the previous trial. By suggesting a two-stage preparation model in which switches as well as repetitions benefit both from time-based transition expectancy, although apparently with different cognitive processes being involved, the present study provides important impulses for future research on the cognitive processes underlying human task-switching behavior., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2021 The Author(s).)

Humans form associations between time intervals and subsequent events and thus develop time-based expectancies that enable time-based action preparation. For instance, when each of two foreperiods (short vs. long) is frequently paired with one specific task (e.g., number magnitude judgment vs. number parity judgment) and infrequently with the alternative task, participants are faster to respond to frequent rather than infrequent foreperiod-task combinations. Here, we investigated the time course of time-based task expectancy by measuring eye movements toward a left and right target location. Foreperiods predicted target locations with 100% validity and tasks with 90% validity. In 2 experiments, without having any explicit knowledge about the foreperiod-location or foreperiod-task contingencies, participants first moved their eyes to the location associated with the short foreperiod and then looked toward the location of the long foreperiod (if no stimulus had been presented after the short foreperiod had passed). That is, they proactively moved their eyes to optimize perception in line with the specific time and location they expected an event to occur at. Importantly, these eye movements reflected not only time-based location expectations, but also time-based task expectations. We discuss new insights in time-based expectancy and its temporal dynamics obtained from anticipatory eye movements and highlight spontaneous eye movements as a window into cognitive processes that cannot be assessed via behavioral response measures. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Recent studies in the field of task switching have shown that humans can base expectancies for tasks on temporal cues. When tasks are predictable based on the duration of the preceding pre-target interval, humans implicitly adapt to this predictability, indicated by better performance in trials with validly compared to invalidly predicted tasks. Yet, it is not clear which internal timing mechanisms are involved. Previous research has suggested that intervals from the sub- and supra-second range are processed by distinct cognitive timing systems. As earlier studies on temporally predictable task switching have used predictive intervals stemming from both ranges, it was not yet clear if the time-based expectancy effect was driven by just one of the two internal timing systems. The present study used clearly sub-second intervals (10 ms and 500 ms) in Experiment 1, while clearly supra-second intervals (1500 ms and 3000 ms) were used in Experiment 2. Substantial adaptation effects were observed in both experiments, showing that sub- as well as supra-second timing systems are involved in time-based expectancies for tasks. The present findings offer important implications for our theoretical understanding of the internal timing mechanisms involved in time-based task expectancy.

In many situations, people have to switch between different tasks. Previous research has shown that task switching leads to relatively slow responses and high error rates. In many real-life task-switching contexts, tasks are not randomly distributed over time, but the temporal distribution of tasks carries information. Often the delay before a task predicts to some degree which task it will be, like when a longer browser loading time for a website makes the search for an alternative more likely. The present study investigated whether and how humans adapt to such temporal regularities. In a series of five experiments, intertask delays predicted with different probabilities the task in the upcoming trial, or whether the task switches in the upcoming trial. Participants adapted their response behavior to the predictability of the task, for all tested degrees of predictability (70%, 80%, 90%), but only for the degree of 90% predictability when the task transition was temporally predictable. The adaptation was implicit and task repetitions as well as switches, both benefitted from this adaptation. Likewise, performance after 500 ms and 1,500 ms delays was facilitated by time-based predictability. The results are discussed in the context of previous findings on nontemporal task predictability. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)

Recent research on time-based expectancy has shown that humans base their expectancies for responses on representations of temporal relations (e.g., shorter vs. longer duration), rather than on representations of absolute durations (e.g., 500 vs. 1000 ms). In the present study, we investigated whether this holds also true for time-based expectancy of tasks instead of responses. Using a combination of the time-event correlation paradigm and the standard task-switching paradigm, participants learned to associate two different time intervals with two different tasks in a learning phase. In a test phase, the two intervals were either globally prolonged (Experiment 1), or shortened (Experiment 2), and they were no longer predictive for the upcoming task. In both experiments, performance in the test phase was better when expectancy had been defined in relative terms and worse when expectancy had been defined in absolute terms. We conclude that time-based task expectancy employs a relative, rather than an absolute, representation of time. Humans seem to be able to flexibly transfer their time-based task expectancies between different global timing regimes. This finding is of importance not only for our basic understanding of cognitive mechanisms underlying time-based task expectancy. For human-machine applications, these results mean that adaptation to predictive delay structures in interfaces survives globally speeding up or slowing down of delays due to different transmission rates.