A wealth of research in neuroscience and developmental psychology has documented the lasting detrimental effects of adverse early-life experiences on health and psychological well-being. To investigate these effects, researchers have developed self- and informant-report questionnaires, interview-based instruments, and experimental paradigms designed to assess exposure to early adversity, model its consequences under controlled laboratory conditions, and investigate the neurobiological mechanisms involved. In contrast, the role of positive early-life experiences in biobehavioral trajectories and adaptive functioning has received comparatively less empirical and theoretical attention. The existing work has largely conceptualized positive experiences in terms of their protective or buffering effects in the context of adversity, and/or their promotive role and independent contribution to physical and psychological well-being. Against this background, this narrative review comprehensively synthesizes (i) current definitions of positive early-life experiences, (ii) tools for their retrospective assessment, and (iii) experimental approaches aimed at manipulating and promoting such experiences in humans. Furthermore, this review advances time-sensitive and individual-centered attention for the study of positive early-life experiences, in which health- and well-being-promoting interventions are informed by an expanding understanding of normative human neuroplasticity as a heterosynchronous process and by dynamic, interdependent interactions operating across individual, family, and societal levels.

Background/Objectives: The concept of Cognitive Reserve (CR) has assumed a central role in research on the prevention of cognitive decline. The term refers to the brain’s capacity to manage age-related changes or pathologies by enhancing neural efficiency and utilizing alternative networks or more efficient cognitive strategies. In human subjects, CR is commonly estimated through indicators such as educational attainment, occupational complexity, and involvement in leisure activities. Leisure activities have been identified as a significant behavioral indicator and can be classified into three main subcomponents: cognitive, physical, and social activities. This narrative review aims to summarize how leisure activities provide cognitive and/or emotional benefits and how these activities help build CR and brain resilience. Methods: Given the conceptual and methodological heterogeneity of this literature, a narrative review design was adopted for an integrative synthesis across cognitive, social, and physical domains in healthy individuals aged 18 and older. Selected studies’ primary outcomes were cognitive and/or emotional effects, with neurophysiological effects as secondary outcomes, a prerequisite for inclusion. Results: Across adulthood, participation in cognitive, social, and physical leisure activities was consistently associated with better cognitive performance and emotional well-being, with cognitive activities more closely linked to cognitive gains and social and physical activities more closely linked to combined benefits; however, evidence is observational or short-term, limiting causal inference. Conclusions: Leisure activities are consistently associated with cognitive and emotional well-being in healthy adults and may support CR development, although longitudinal and intervention research is needed to clarify causal pathways and confounders such as education and socioeconomic status.