Simon Hass ¹ Maxie Liebscher ¹ Anni Richter ^2,3,4 Klaus Fliessbach ^5,6 Christoph Laske ^7,8 Sebastian Sodenkamp ^7,9 Oliver Peters ^10,11,12 Julian Hellmann-Regen ^10,11,12 Ersin Ersoezlue ^10,11,12 Josef Priller ^10,13,14,15 Eike Jakob Spruth ^10,13 Slawek Altenstein ^10,13 Sandra Roeske ⁵ Anja Schneider ^5,6 Hartmut Schuetze ¹⁶ Annika Spottke ^17,5 Anna Esser ⁵ Stefan Teipel ^18,19 Ingo Kilimann ^18,19 Jens Wiltfang ^20,21,22,5 Ayda Rostamzadeh ²³ Wenzel Glanz ¹⁶ Enise I. Incesoy ^16,24,25 Falk Luesebrink ¹⁶ Peter Dechent ²⁶ Stefan Hetzer ²⁷ Klaus Scheffler ²⁸ Michael Wagner ^5,6 Frank Jessen ^23,29,5 Emrah Duezel ^16,24 Franka Gloeckner ³⁰ Bjoern Hendrik Schott ^2,20,21,5 Miranka Wirth ^1* Olga Klimecki ^1,31

• ¹ German Center for Neurodegenerative Diseases (DZNE), Dresden, Lower Saxony, Germany
• ² Leibniz Institute for Neurobiology (LG), Magdeburg, Saxony-Anhalt, Germany
• ³ German Center for Mental Health (DZPG), Halle-Jena-Magdeburg, Germany
• ⁴ German Center for Mental Health, Center for Intervention and Research On Adaptive and Maladaptive Brain Circuits Underlying Mental Health (C-I-R-C), Halle-Jena-Magdeburg, Germany
• ⁵ German Center for Neurodegenerative Diseases, Helmholtz Association of German Research Centers (HZ), Bonn, North Rhine-Westphalia, Germany
• ⁶ University Hospital Bonn, Bonn, North Rhine-Westphalia, Germany
• ⁷ German Center for Neurodegenerative Diseases (DZNE), Tübingen, Baden-Württemberg, Germany
• ⁸ Section for Dementia Research, Hertie Institute for Clinical Brain Research, Tübingen, Baden-Württemberg, Germany
• ⁹ Department of Psychiatry and Psychotherapy, University Hospital Tübingen, Tübingen, Baden-Württemberg, Germany
• ¹⁰ German Center for Neurodegenerative Diseases (DZNE), Berlin, Baden-Württemberg, Germany
• ¹¹ Department of Psychiatry and Neurosciences, Charité University Medicine Berlin, Berlin, Baden-Württemberg, Germany
• ¹² Experimental and Clinical Research Center, Charite University Medicine Berlin, Berlin, Baden-Wurttemberg, Germany
• ¹³ Department of Psychiatry and Psychotherapy, Charité University Medicine Berlin, Berlin, Baden-Wurttemberg, Germany
• ¹⁴ Department of Psychiatry and Psychotherapy, University Hospital rechts der Isar, Technical University of Munich, Munich, Bavaria, Germany
• ¹⁵ UK Dementia Research Institute, University of Edinburgh, Edinburgh, Scotland, United Kingdom
• ¹⁶ German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Saxony-Anhalt, Germany
• ¹⁷ Department of Neurology, University Hospital Bonn, Bonn, North Rhine-Westphalia, Germany
• ¹⁸ German Center for Neurodegenerative Diseases (DZNE), Rostock, Mecklenburg-Vorpommern, Germany
• ¹⁹ Department of Psychosomatic Medicine, Rostock University Medical Center, Rostock, Mecklenburg-Vorpommern, Germany
• ²⁰ German Center for Neurodegenerative Diseases, Helmholtz Association of German Research Centers (HZ), Bonn, Lower Saxony, Germany
• ²¹ Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Goettingen, Lower Saxony, Germany
• ²² Neurosciences and Signaling Group, Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
• ²³ Department of Psychiatry, University of Cologne, Medical Faculty, Cologne, North Rhine-Westphalia, Germany
• ²⁴ Institute of Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University, Magdeburg, Saxony-Anhalt, Germany
• ²⁵ Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Otto von Guericke University Magdeburg, Magdeburg, Saxony-Anhalt, Germany
• ²⁶ MR-Research in Neurosciences, Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Lower Saxony, Germany
• ²⁷ Berlin Center for Advanced Neuroimaging (BCAN), Berlin, Baden-Württemberg, Germany
• ²⁸ Department for Biomedical Magnetic Resonance, University of Tübingen, Tubingen, Germany
• ²⁹ Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Faculty of Medicine, University of Cologne, Cologne, North Rhine-Westphalia, Germany
• ³⁰ Chair of Lifespan Developmental Neuroscience, Technical University Dresden, Dresden, Lower Saxony, Germany
• ³¹ Chair of Biopsychology, Technical University Dresden, Dresden, Lower Saxony, Germany

Background. In humans, environmental enrichment (EE), as measured by the engagement in a variety of leisure activities, has been associated with larger hippocampal structure and better memory function. The present cross-sectional study assessed whether EE during early life (13-30 years) and midlife (30-65 years) is associated with better preserved memory-related brain activity patterns in older age. Methods. In total, 372 cognitively unimpaired older adults (aged ≥ 60 years old) of the DZNE-Longitudinal Study on Cognitive Impairment and Dementia (DELCODE; DRKS00007966) were investigated. EE was operationalized using items of the Lifetime of Experiences Questionnaire (LEQ), which measures the self-reported participation in a variety of leisure activities in early life and midlife. The preservation of memory-related functional brain activity was assessed using the FADE and SAME scores, which relate older adults' brain activity patterns in the temporo-parieto-occipital memory network to those of young adults during visual memory encoding.Results. EE during early life and midlife was significantly associated with higher SAME scores during novelty processing (N = 372, β = 0.13, p = .011). Thus, older participants with higher EE showed greater similarity in functional brain activity patterns during novelty processing with young adults. This positive association was observed most strongly in participants with subjective cognitive decline (SCD, N = 199, β = 0.20, p = .006).More frequent participation in a variety of leisure activities in early life and midlife is associated with more successful aging of functional brain activity patterns in the memory network of older adults, including participants at increased risk for dementia.Longitudinal studies are needed to clarify whether higher EE during life could help preserve memory network function in later life.