BACKGROUND: Cognition is a neurocognitive test battery created at the University of Pennsylvania and adapted by the National Aeronautics and Space Administration (NASA). It comprises 10 neurocognitive tests that examine multiple domains, and has been validated in a normative sample of STEM-educated adults and compared to NASA’s WinSCAT battery.METHODS: The purpose of this study was to follow the original sample to assess Cognition and WinSCAT’s test-retest reliability and age, sex, and test-retest interval effects on performance.RESULTS: Performance on both Cognition and WinSCAT decreased with age but improved with repeated administration due to practice effects, and men had higher scores than women on tasks that required vigilant attention, spatial reasoning, and risk-taking behaviors. Assessment of test-retest reliability showed intraclass coefficients for efficiency ranging from 0.417 to 0.810, reflecting the broad nature of constructs assessed by Cognition.DISCUSSION: Results largely matched predictions, with some counter-intuitive results for test-retest reliability interval.Lee G, Moore TM, Basner M, Nasrini J, Roalf DR, Ruparel K, Port AM, Dinges DF, Gur RC. Age, sex, and repeated measures effects on NASA’s “Cognition” Test Battery in STEM educated adults. Aerosp Med Hum Perform. 2020; 91(1):18–25.