ABSTRACT (Project 1) Project 1 will leverage the SuperAging Consortium to test the supposition that SuperAgers have relatively preserved physiologic and behavioral complexity, compared to Controls, in the domains of physical activity, autonomic responsivity (e.g., blood pressure, heart rate), sleep, and social engagement. The number of people 80 years and older is expected to triple to ~ 426 million by the year 2050 making successful aging an essential social and economic priority. Typical aging is associated with challenges responding dynamically to heightened system demands (internal or external). This loss of responsiveness, and/or ability to stabilize the system, (framed theoretically as a ‘loss’ of physiologic and behavioral ‘complexity’) accounts for a number of age-related declines in neural connectivity, balance control, memory, among others. However, SuperAgers appear immune to some age-related cognitive changes, and thus represent an ‘ideal’ aging target. Whilst SuperAgers self-report increased physical activity and social engagement compared to their Controls, little is known about the actual physiologic and behavioral differences that distinguish SuperAgers. This is a critical missing link in understanding processes that underlie potential pathways to successful aging. The SuperAging Consortium offers a unique opportunity to reveal this missing link, and importantly, to do so in a diverse cohort. Understanding how loss of complexity manifests in everyday activities requires sensitive, multiple time-scale, measurements capable of capturing dynamic and complex behaviors in a way not afforded by point-in-time and clinical assessments. We will collect mechanoacoustic sensor recordings, during every day activities, over 24-hour time periods for two weeks in both SuperAgers and their Controls co-enrolled with the Clinical/Imaging Core. Using multiscale entropy approaches we will generate a ‘complexity’ score that captures the quality, quantity, range, and consistency of physical activity, autonomic nervous system function, sleep, and social engagement behaviors within, and across, days. In Aim 1, we will determine whether loss of complexity in physical activity and autonomic nervous system (ANS) activity differentiates SuperAgers from Controls. In Aim 2, we will determine whether loss of complexity in sleep quality and ANS activity during sleep differentiates SuperAgers from Controls. In Aim 3, we will determine whether complexity in social engagement differentiates SuperAgers from Controls. We predict that compared to their Controls, SuperAgers will demonstrate higher physical activity complexity and higher autonomic function complexity reflecting greater overall levels and quality of physical activity; lower (i.e., better) sleep complexity scores reflecting lower variability in sleep patterns; and higher social engagement complexity scores suggesting they are more consistently engaged in verbal activities compared to typical agers. Projec...