SLEEP AND PRIOR KNOWLEDGE SHAPE LONG-TERM SCHEMA FORMATION AND MEMORY REORGANIZATION

New memories initially depend on the hippocampus but gradually become supported by neocortical networks through systems consolidation—a process facilitated by sleep. When new information aligns with existing knowledge structures, or schemas, this consolidation may be accelerated, potentially supported by sleep spindles that enhance schema-related integration and reduce hippocampal reliance. I will present a novel virtual environment enabling the study of schema formation and updating over an extended period. Twenty-five participants are trained on this task over six months, with six experimental visits: two visits during the first week to capture early phases of schema formation, two visits at three months to examine the continued development and updating of the spatial schema, and two visits at six months to assess updating of a well-established schema. At each time point, visits are counterbalanced across sleep and wake conditions. At the behavioral level, we observe progressive integration of an increasing number of object–location associations over time, consistent with gradual schema formation. Planned fMRI analyses will track the shift from hippocampal to retrosplenial cortex engagement during object–location learning modulated by prior knowledge & sleep. Hippocampal independence after 48h during schema updating has already been shown in a corresponding rodent task. Together, these human and animal findings will clarify how prior experience & sleep shape memory reorganization in the brain.