 We expect the results of this pilot study to justify a larger study that follows people to determine if certain tests of memory and attention, performed while sleepiness is induced by a single dose of lorazepam a widely used anti-anxiety medication could predict an individuals risk of developing AD. We plan to compare cognitively normal people who possess a common gene that increases risk for AD the apolipoprotein E APOE e4 alleleto individuals without this gene. We hypothesize that a single 2 mg dose of lorazepam will cause more cognitive impairment in carriers of the APOE e4 allele than in noncarriers, and that the carriers will recover more slowly from these impairments than noncarriers. 