Swimming expertise is associated with enhanced suprasecond visual duration discrimination across silent and rhythmic contexts.

Background and aims: Whether athlete advantages in temporal processing primarily reflect sport-specific temporal knowledge or transfer to neutral laboratory judgments remains unresolved. Competitive swimming offers a theoretically informative case because successful performance depends on the precise regulation of pace and rhythm across repeated actions in a sensory-constrained environment. The present study examined whether swimming expertise is associated with superior performance in a neutral visual suprasecond duration-discrimination task and whether any expertise-related advantage remains observable across sensory contexts. Methods: Two independent experiments were conducted, each including 20 Expert Swimmers and 20 Amateur Controls. Participants completed a visual two-alternative forced-choice duration-discrimination task in which task difficulty was manipulated by the between-interval duration difference (200, 500, 1,000, and 2,000 ms). Experiment 1 was administered under silent visual conditions, whereas Experiment 2 used the same visual task while presenting task-irrelevant rhythmic auditory stimulation concurrently with each visual interval. Accuracy and reaction time (RT) were analyzed separately within each experiment. Results: In both experiments, discrimination accuracy increased as task difficulty decreased, confirming the effectiveness of the difficulty manipulation. Across difficulty levels, Expert Swimmers showed higher accuracy than Amateur Controls under both silent and task-irrelevant rhythmic conditions. Evidence for a larger expert advantage under higher difficulty emerged in Experiment 1 but was not reproduced in Experiment 2. Reaction-time findings did not indicate a generalized speed advantage, although difficulty-related variation in response patterning was observed. The rhythmic auditory background did not materially alter the overall accuracy advantage shown by Expert Swimmers. Conclusion: Swimming expertise was associated with enhanced performance in a neutral visual suprasecond duration-discrimination task across two sensory contexts. These findings indicate that the observed advantage was expressed primarily in discrimination accuracy rather than generalized response speed and remained observable when the task was embedded in a task-irrelevant rhythmic context. More broadly, the results support a bounded-transfer interpretation: swimmer expertise appears to extend beyond overtly sport-specific temporal content, but the present evidence does not support claims of unrestricted domain-general timing.