Human Experimental Procedures Cognitive function was assessed using a battery of wellvalidated and widely available neuropsychological subtests. Because participants were from either of two parent studies with different neuropsychological batteries, subtests with similar content and administration procedures [e.g., Digit Span from the Wechsler Adult Intelligence Test, Third Edition (WAIS-III) (Wechsler 1997) and Digit Span from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) (Randolph 1998)] were analyzed together in the present analyses, and all subtest scores were converted to z scores using well-validated norms as summarized by cognitive domain in Supplementary