The association between Internet use and cognitive function among older Chinese adults: a moderated mediation model

Background: Previous studies have found a significant link between internet use and cognitive function in older adults. However, the underlying mechanisms of this relationship have not been thoroughly explored. This study aims to investigate the mediating role of social and family-level interactions in the relationship between internet use and cognitive function in older adults, as well as how age moderates this relationship. Methods: The data for this study were derived from the China Health and Retirement Longitudinal Study (CHARLS, N = 7090) organized by the National School of Development at Peking University in 2020. We first examined a simple mediation model in which social participation served as a mediator between internet use and cognitive function. Additionally, age was systematically incorporated as a moderator in the model. Moderated mediation analysis was conducted using the PROCESS macro developed by Hayes. Results: Based on the mediation analysis results, the relationship between internet usage and cognitive function is partially mediated by societal-level interaction and family-level interaction. Specifically, internet usage significantly influences societal-level interaction (B = 0.947, 95% CI = [0.674, 0.892]), and societal-level interaction significantly influences cognitive function (B = 0.196, 95% CI = [0.134, 0.258]). In contrast, internet usage significantly negatively influences family-level interaction (B = -1.880, 95% CI = [-2.619, -1.143]), and family-level interaction significantly influences cognitive function (B = -0.016, 95% CI = [-0.025, -0.007]). Moderator mediation analysis reveals that age not only significantly moderates the direct effect path of internet usage on cognitive function (B = 0.66, 95% CI = [0.07, 1.24]) but also moderates the path through which family-level interaction influences cognitive function (B = 0.12, 95% CI = [0.02, 0.23]). Conclusion: This study provides new insights into the mechanisms linking internet use, social and family interactions, and cognitive function, thereby contributing to existing research on cognitive health. The findings offer valuable references for developing interventions aimed at improving cognitive health in older adults.