R Glenn Weaver, Michael W Beets, Jennifer Huberty, Darcy Freedman, Gabrielle Turner-Mcgrievy, Diane Ward
Physical activity opportunities in afterschool programs
Health promotion practice
studied brain volume loss old age affected age apoe gene sex level education completed quantitative characterization brain volume loss old age relative young age requiresat least principletwo mri scans one performed young age one old age however way address problem one mri scan obtained old age computed total brain losses elderly subjects ratio estimated brain volume estimated total intracranial volume magnetic resonance imaging mri scans 890 healthy subjects aged 70 85 years assessed causal analysis factors affecting brain atrophy performed using probabilistic bayesian modelling mathematics causal inference found age sex causally related brain atrophy women reaching elderly age 1 larger brain volume relative intracranial volume men brain ages rationale sex differences brain volume losses adult lifespan questions need addressed causal inference empirical data graphical causal modelling presented instrumental understanding puzzling scientific area studythe biological aging brain