Informed consent was obtained from all participants. For neurophysiological assessments, experimental protocols were approved by each study site’s institutional review board. Further, participants were excluded from neurophysiological assessments, if they had positive breath-analyzer test and/or urine screen results; hepatic encephalopathy/cirrhosis of the liver; history of head injury, seizures, or neurosurgery; uncorrected sensory deficits; history/symptoms of psychoses; self-reported positive test result for human immunodeficiency virus; other acute/chronic medical illnesses that affect brain function; or psychotropic medications that affect electrophysiologic measurement. Accordingly, a total of 7,516 subjects (MERPage=32.55; SD=13.26) had P3 data that were used in this study.
