Participants were enrolled in the Hillblom Aging Network at the University of California, San Francisco (UCSF) Memory and Aging Center. All participants underwent comprehensive neurobehavioral evaluations and met the following inclusionary criteria at baseline: 1) clinically normal based on consensus conference with a neurologist and board-certified neuropsychologist; 2) no history of neurological disorder known to impact cognition (e.g., epilepsy, stroke); and 3) functionally intact as defined by an informant-obtained CDR global score of 0 (Morris, 1993). More specifically, the determination of clinically normal by consensus conference involved ruling out the presence of mild cognitive impairment, dementia, or any other neurological condition resulting in cognitive, behavioral, motor, or functional decline (e.g., Parkinson’s disease), according to widely used diagnostic criteria (e.g., Albert et al., 2011; Armstrong et al., 2013; Gorno-Tempini et al., 2011; Höglinger et al., 2017; McKeith et al., 2017; McKhann et al., 2011; Postuma et al., 2015; Rascovsky et al., 2011). Three main sources of information were considered by the neurologist and neuropsychologist during the diagnostic conference. First, participants underwent a thorough evaluation with the neurologist that involved a comprehensive neurological examination, clinical interview, and review of systems. Second, neuroimaging (structural MRI) was reviewed to screen out gross brain pathology with potential to negatively impact cognition (e.g., tumor). Third, participants completed a battery of neuropsychological tests to objectively assess major domains of cognitive function, including attention, executive functioning, memory, language, and visuospatial skills. Cognitive impairment was defined by the presence of subjective cognitive decline, as reported by the participant or informant, together with objective performance on neuropsychological testing that was below expectation given the participant’s age and level of premorbid functioning (Albert et al., 2011). In making the determination of clinically normal, emphasis was placed on ruling out any declines in the participant’s ability to perform everyday tasks due to cognitive changes.

University of California San Francisco Alzheimer’s Disease Research Center under grant P30AG062422;

Larry L. Hillblom Network under Grant 2014-A-004-NET;

R01AG032289 (PI: JK);

R01AG048234 (PI: JK)

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