Neighborhood Bonding and Bridging Social Capital, Social Activity Participation, and Short-term Cognitive Variability in Later Life

Investigating social determinants of health and related outcomes may help identify effective and sustainable intervention targets. This study examined whether contextual-level social capital (bonding and bridging capital) and individual-level social participation were associated with short-term cognitive variability, an early indicator of normal and pathological cognitive aging. The sample consisted of urban community-dwelling older adults (N = 304, mean age = 77.5, range = 70-91) from the Einstein Aging Study. Bonding and bridging social capital measures were derived at the zip code tabulation area (ZCTA)-level and linked with participants' addresses. Formal and informal social activity participation was assessed using self-reported questionnaires. Cognitive performance was assessed using three smartphone-administered cognitive tasks that measured processing speed (Symbol match) and associative working memory performance (Color-shape binding, Color-dot) 6 times a day for 14 days. Heterogeneous variance multilevel models using log-linear prediction of residual variance were used to simultaneously assess mean and variability of cognitive performance. Both social capital measures were significantly associated with reduced cognitive variability across the three tests, with stronger effects of bridging (6.3∼8.8% reduction in residual variance) than bonding social capital (3.3∼5.4% reduction). Social participation was independently associated with reduced cognitive variability (3.0∼8.6% reduction). Effects of social capital and social participation on mean levels of cognition mostly failed to reach statistical significance. Both structural and individual-level social integration played a crucial role in short-term cognitive variability beyond mean-level performance. Multi-level interventions aimed at strengthening social ties and engagement might mitigate cognitive instability and future cognitive impairment.