[P2] Poster: Day 2

[P2-06] Electrophysiological signatures of post-interval activity in explicit and implicit timing

*Mariagrazia Capizzi¹, Cristina Narganes Pineda¹, Pom Charras³, Giovanna Mioni², Antonino Visalli⁴ (1. Mind, Brain and Behavior Research Center (CIMCYC), University of Granada; Department of Experimental Psychology, University of Granada, Granada, Spain (Spain), 2. Department of General Psychology, University of Padua, Padua (Italy), 3. Univ Paul Valéry Montpellier 3, EPSYLON EA 4556, F34000, Montpellier, France (France), 4. Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia (Italy))

Keywords:

Time discrimination,Explicit processing,Implicit processing,ERPs

The distinction between explicit and implicit timing in the processing of millisecond-to-second intervals is gaining attention in timing research. Explicit timing involves the deliberate estimation of time in tasks that require overt temporal judgments, whereas implicit timing occurs incidentally in tasks where time is not the primary focus, yet temporal processing still influences behavior. Whether explicit and implicit timing rely on shared or distinct neural mechanisms remains an open question. In the present study, we addressed this issue by directly comparing explicit and implicit timing tasks, paired with electrophysiological (EEG) recording. In the explicit timing task, participants judged whether a comparison interval was shorter or longer than a standard interval. In the implicit timing task, participants judged whether a comparison color was more reddish or yellowish than a standard color. Durations and colors were fully orthogonalised across the two tasks, ensuring that the only difference lay in the task instructions, which directed attention either to duration or to color. Event-related potentials (ERPs) were time-locked to the offset of the comparison intervals, either attended or unattended depending on the task. Behaviorally, we found that the color dimension was irrelevant for the temporal discrimination task. In contrast, the implicit temporal manipulation influenced color perception, with shorter durations leading participants to perceive colors as brighter. EEG results showed that temporal processing modulated early components over central scalp electrodes in a similar manner across both explicit and implicit tasks. In contrast, a sustained activity pattern with a frontal-posterior bipolar distribution emerged, indicating differential engagement depending on task demands. Overall, our results suggest that explicit and implicit timing shape behavior via both shared and distinct neural mechanisms.