Learning to recover weak signals: A two-stage graph-based framework for all-weather RGB-T object detection.

Ikigai, as a term originating from Japanese culture, is a concept that encompasses diverse interpretations reflecting its multifaceted nature. Mathews [] defines Ikigai as “life worth living,” while Hasegawa et al. [] describe it as “meaning in life.” Kamiya [] offers additional perspectives, characterizing Ikigai as both “purpose in life” and “reason for living.” In a broad sense, Ikigai can be conceptualized as the foundation of an individual's survival and the driving force that imbues life with purpose and direction []. Furthermore, lexicographical definitions highlight Ikigai as both “enjoying the happiness and contentment of life” and “understanding the significance and worth of one's own existence” []. Empirical studies have shown that having Ikigai is associated with a range of positive health outcomes. The Japan Collaborative Cohort Study demonstrated that individuals with Ikigai exhibited a significantly lower risk of all‐cause mortality []. Longitudinal evidence from a large‐scale outcome‐wide analysis among older adults in Japan further reported that Ikigai predicted a reduced incidence of functional disability, dementia, and depressive symptoms, as well as higher subjective well‐being and life satisfaction []. Cross‐sectional research also supports the link between Ikigai and better quality of life, suggesting that Ikigai may serve as a protective psychosocial resource []. Collectively, these studies underscore Ikigai as a key determinant of physical, cognitive, and emotional health among older adults. Social interaction is commonly defined as interpersonal behaviors and relationships through which individuals fulfill personal needs, and more broadly, the extent of engagement with one's environment []. It is increasingly understood as a dynamic and multidimensional process embedded in daily life, encompassing not only direct interpersonal exchanges but also the functional and motivational capacities that enable older adults to initiate and sustain engagement with others and with the surrounding environment over time []. Social interaction is associated with both physical [] and mental health [], while poor or limited interaction is linked to functional decline, higher mortality [], dementia [], and depressive symptoms []. A substantial body of longitudinal research has demonstrated that various indicators of social relationships, such as social interaction, social participation [], social support [], loneliness [], and social isolation [], are associated with mental health outcomes among older adults, encompassing both negative indicators such as depressive symptoms and anxiety [], and positive indicators such as happiness [] and life satisfaction []. Some studies have further applied longitudinal structural equation modeling approaches, including the cross‐lagged panel model (CLPM) [, , ], to examine temporal ordering and dynamic interrelations between social relationship indicators and mental health outcomes among older adults. For example, a CLPM analysis in a nationally representative cohort of British adults suggested bidirectional associations between social isolation and depressive symptoms over time []. Cross‐lagged findings for loneliness and depressive symptoms have also indicated temporal links, although the strength and symmetry of reciprocal paths may vary across studies and model specifications []. Within this broader framework, Ikigai, as a culturally grounded positive psychological concept, is closely related to various forms of social interaction with accumulating evidence. Previous studies have reported that engagement in community‐based activities [], involvement in volunteer programs [], and regular and sustained social participation [] are associated with a higher likelihood of reporting Ikigai. However, despite these consistent associations, most existing studies have relied on cross‐sectional designs, leaving the temporal direction of the relationship between social interaction and Ikigai unresolved. Although a small number of longitudinal studies exist, they have typically focused on unidirectional pathways and have not formally tested reciprocal dynamics between these constructs [].