Retrieval practice promotes semantic integration of real-world memories without compromising episodic integrity

Actively recalling information is a well-established memory strengthening technique that reliably outperforms passive review. Termed "the testing effect," retrieval practice may promote semantic transformation and reshape related, unreviewed episodic information, beyond merely strengthening reviewed content. These broader effects of retrieval practice are difficult to capture with simplified laboratory materials but can be examined using rich, real-world events that evolve across multiple episodic and semantic dimensions. However, retrieval practice's impact on such real-world memories remains poorly understood. We therefore investigated how actively retrieving event details (retrieval practice) versus passively reviewing the same details (restudy) influenced memory for an episodically rich staged event after two weeks (n = 26 per group). Retrieval increased the incorporation of preexisting semantic information into recall narratives, with greater semantic integration after retrieval practice predicting more episodically rich narratives. These findings suggest that retrieval practice enhanced integration of event details with semantic knowledge, perhaps via co-activation of semantically related content during retrieval. We found tentative evidence of a testing effect for real-world events: Retrieval improved retention of tour details (so long as they were successfully retrieved during retrieval practice) but did not otherwise affect broader episodic memory for unreviewed content, narrative accuracy, narrative temporal and semantic organization, or subjective phenomenology. Together, these findings suggest that retrieval reshapes memories by integrating recalled content into semantic knowledge networks, while preserving the overall integrity of episodic representations. Our work reveals that the testing effect may be underpinned by distinct transformations of episodic and semantic memory, with semantic transformation enhancing rather than compromising episodic richness.