The dopamine clock hypothesis suggests that the dopamine level determines the speed of the hypothetical internal clock. However, dopaminergic function has also been implicated for motivation and thus the effect of dopaminergic manipulations on timing behavior might also be independently mediated by altered motivational state. Studies that investigated the effect of motivational manipulations on peak responding are reviewed in this paper. The majority of these studies show that a higher reward magnitude leads to a leftward shift, whereas reward devaluation leads to a rightward shift in the initiation of timed anticipatory behavior, typically in the absence of an effect on the timing of response termination. Similar behavioral effects are also present in a number of studies that investigated the effect of dopamine agonists and dopamine-related genetic factors on peak responding. These results can be readily accounted for by independent modulation of decision-thresholds for the initiation and termination of timed responding.
Başak Akdoğan, Fuat Balcı and Hedderik van Rijn
Forming temporal expectations plays an instrumental role for the optimization of behavior and allocation of attentional resources. Although the effects of temporal expectations on visual attention are well-established, the question of whether temporal predictions modulate the behavioral outputs of the autonomic nervous system such as the pupillary response remains unanswered. Therefore, this study aimed to obtain an online measure of pupil size while human participants were asked to differentiate between visual targets presented after varying time intervals since trial onset. Specifically, we manipulated temporal predictability in the presentation of target stimuli consisting of letters which appeared after either a short or long delay duration (1.5 vs. 3 s) in the majority of trials (75%) within different test blocks. In the remaining trials (25%), no target stimulus was present to investigate the trajectory of preparatory pupillary response under a low level of temporal uncertainty. The results revealed that the rate of preparatory pupillary response was contingent upon the time of target appearance such that pupils dilated at a higher rate when the targets were expected to appear after a shorter as compared to a longer delay period irrespective of target presence. The finding that pupil size can track temporal regularities and exhibit differential preparatory response between different delay conditions points to the existence of a distributed neural network subserving temporal information processing which is crucial for cognitive functioning and goal-directed behavior.
Ceyda Sayalı, Ezgi Uslu, Melisa Menceloğlu, Reşit Canbeyli and Fuat Balcı
Timing is an integral part of physical activities. Walking as a routine form of physical activity might affect interval timing primarily in two different ways within the pacemaker–accumulator timing-theoretic framework: (1) by increasing the speed of the pacemaker due to its physiological effects; (2) by decreasing attention to time and consequently slowing the rate of temporal integration by serving as a secondary task. In order to elucidate the effect of movement on subjective time, in two different experiments we employed a temporal reproduction task conducted on the treadmill under four different encoding–decoding conditions: (1) encoding and reproducing (decoding) the duration while standing (rest); (2) encoding the duration at rest and reproducing it while moving: (3) both encoding and reproducing the duration while moving; and (4) encoding the duration while moving and reproducing it at rest. In the first experiment, participants were tested either in the 4 or the 8 km/h movement condition, whereas in the second experiment a larger sample was tested only in the 4 km/h movement condition. Data were de-trended to control for long-term performance drifts. In Experiment 1, overall durations encoded at rest and reproduced during motion were under-reproduced whereas durations encoded during motion and reproduced at rest were over-reproduced only in the 8 km/h condition. In Experiment 2, the same results were observed in the 4 km/h condition with a larger sample size. These effects on timing behavior provide support for the clock speed-driven effect of movement and contradicts the predictions of attention-based mediation.
Edited by Argiro Vatakis, Fuat Balcı, Massimiliano Di Luca and Ángel Correa
Contributors are: Patricia V. Agostino, Rocío Alcalá-Quintana, Fuat Balcı, Karin Bausenhart, Richard Block, Ivana L. Bussi, Carlos S. Caldart, Mariagrazia Capizzi, Xiaoqin Chen, Ángel Correa, Massimiliano Di Luca, Céline Z. Duval, Mark T. Elliott, Dagmar Fraser, David Freestone, Miguel A. García-Pérez, Anne Giersch, Simon Grondin, Nori Jacoby, Florian Klapproth, Franziska Kopp, Maria Kostaki, Laurence Lalanne, Giovanna Mioni, Trevor B. Penney, Patrick E. Poncelet, Patrick Simen, Ryan Stables, Rolf Ulrich, Argiro Vatakis, Dominic Ward, Alan M. Wing, Kieran Yarrow, and Dan Zakay.
Patrick Simen, Francois Rivest, Elliot A. Ludvig, Fuat Balci and Peter Killeen
Pacemaker-accumulator (PA) systems have been the most popular kind of timing model in the half-century since their introduction by Treisman (1963). Many alternative timing models have been designed predicated on different assumptions, though the dominant PA model during this period — Gibbon and Church’s Scalar Expectancy Theory (SET) — invokes most of them. As in Treisman, SET’s implementation assumes a fixed-rate clock-pulse generator and encodes durations by storing average pulse counts; unlike Treisman’s model, SET’s decision process invokes Weber’s law of magnitude-comparison to account for timescale-invariant temporal precision in animal behavior. This is one way to deal with the ‘Poisson timing’ issue, in which relative temporal precision increases for longer durations, contrafactually, in a simplified version of Treisman’s model. First, we review the fact that this problem does not afflict Treisman’s model itself due to a key assumption not shared by SET. Second, we develop a contrasting PA model, an extension of Killeen and Fetterman’s Behavioral Theory of Timing that accumulates Poisson pulses up to a fixed criterion level, with pulse rates adapting to time different intervals. Like Treisman’s model, this time-adaptive, opponent Poisson, drift–diffusion model accounts for timescale invariance without first assuming Weber’s law. It also makes new predictions about response times and learning speed and connects interval timing to the popular drift–diffusion model of perceptual decision making. With at least three different routes to timescale invariance, the PA model family can provide a more compelling account of timed behavior than may be generally appreciated.
Silvia Maggi, Luciana Garbugino, Ines Heise, Thierry Nieus, Fuat Balcı, Sara Wells, Glauco P. Tocchini-Valentini, Silvia Mandillo, Patrick M. Nolan and Valter Tucci
Phenotyping behavioral and cognitive processes is a critical practice in mouse research and reliable phenotypic assessment is an essential component of building well-defined links between genes and behavioral/cognitive functions.
The success of behavioral screens in neurobehavioral mouse genetics depends on the identification of reliable, reproducible, and high-throughput behavioral/cognitive measures from individual animals irrespective of the differences in opinions regarding how to tackle phenotyping in different behavioral domains. Furthermore, reliable behavioral assays must be resistant to inevitable environmental differences across laboratories since protocols can be replicated but not all the environmental conditions.
Here we present a cross-laboratory study of interval timing behaviors in mice. Two classically used mouse inbred substrains, C57BL/6J and C57BL/6N, were studied over several days in home-cages containing automated testing apparatus. Remarkably, all timing measures in mouse performance showed a robust reproducibility across centers and even small differences between the two substrains were comparable across laboratories. Moreover, we have observed a consistent increase in error rate during the light phase of the light–dark cycle, which suggests that mouse performance during this phase is compromised by a possible sleep inertia-like effect. Overall, our study demonstrates that analysis of mouse timing behavior can lead to robust and reliable endophenotypes in mouse behavioral genetic studies.