Modality-Specific Consolidation Shapes Long-Term Retention in Statistical Learning

Everyday learning unfolds across multiple senses, yet the long-term retention of multisensory statistical learning (SL) remains poorly understood. SL—the implicit detection and extraction of regularities from continuous input—has been documented across sensory modalities, but most work has focused on immediate learning in unisensory contexts. This study, using a within-subject design, directly compared 24-hour consolidation trajectories of auditory, visual, and audiovisual SL in young adults. Twenty-six participants completed familiarization and an immediate test phase in all three modalities, followed by delayed testing after 24 hours. Multisensory input yielded higher recognition accuracy than unisensory input at both immediate and delayed tests, demonstrating a robust performance advantage. However, only auditory SL showed overnight gains, while visual and multisensory SL remained stable across the retention interval. Cross-task correlations—both within each testing timepoint and for consolidation magnitudes—were weak, suggesting that modality-specific processes make a substantial contribution to SL. These findings provide the first direct evidence on the long-term retention of multisensory SL. While multisensory input boosts overall performance, consolidation trajectories remain constrained by modality-specific mechanisms.