Exploring the malleability of Sensitivity to Intersensory Synchrony in typically developing preschoolers: Insights from single-session Intersensory Synchrony Experiential Practice (ISEP-SS)

Temporal proximity is a fundamental cue for integrating sensory inputs into unified percepts. Sensitivity to Intersensory Synchrony (SIS) enables detection of this cue, fostering intersensory redundancy that not only enriches perception but also appears to support the development of higher-order functions. In adults, single-session perceptual training can enhance SIS with lasting effects, although generalization to untrained stimuli remains unclear. Developmental evidence is scarce. To date, only one study has been conducted, which reported traininginduced enhancements in SIS in six-month-old infants. Given the role of experience in shaping SIS and its rapid refinement during the preschool years, the present study examined whether brief multisensory perceptual training can enhance SIS in typically developing children aged 3 to 6 years. A 20min individually administered playbased multisensory perceptual training was tested in 77 participants versus 62 agematched controls. Training efficacy was examined in relation to Age and Inhibitory Control, assessed prior to training via a standardized test battery. A preferential-looking task administered before and immediately after training revealed a significant enhancement in SIS, reflected in an increased preference for synchronous over asynchronous intersensory events, with effects generalizing to untrained, complex speech stimuli. No age-related differences emerged. Notably, children with lower Inhibitory Control showed the greatest improvements, suggesting that brief multisensory interventions may also benefit atypical developmental profiles characterized by reduced SIS and impaired Inhibitory Control. These findings highlight the potential of a simple, nonverbal, and play-based training to strengthen fundamental perceptual mechanisms thought to support the development of higher-order functions.