Abstract
Natural environments are often treated as a relatively uniform category in cognitive research despite substantial variation in their spatial organization and regularity. This study examined whether episodic memory depends not only on environmental type but also on the internal structure of the environment. Sixty participants experienced four immersive virtual environments in a 2 × 2 within-subject design crossing environmental type (natural vs. urban) with structural regularity (rhythmic vs. irregular). Memory was assessed using free, cued, and delayed recall and analyzed using linear mixed-effects models controlling for presentation order. Immediate recall showed little evidence of environmental effects. In contrast, Cued Recall 1 showed a significant Environment × Regularity interaction, with the irregular natural environment producing the highest performance. Follow-up contrasts showed higher recall in irregular nature than in all three comparison conditions for Cued Recall 1 and Delayed Recall, with a more selective advantage during Cued Recall 2. Retention proportions did not differ across conditions, indicating that delayed differences reflected earlier memory advantages rather than differential forgetting. These findings suggest that episodic memory effects associated with natural environments cannot be understood through a nature–urban distinction alone. Instead, the internal organization of an environment may shape memory, with irregular natural environments potentially providing more distinctive contextual information that becomes particularly useful during context-supported retrieval.