In order to test these hypotheses, the investigators will perform cognitive tests (Iowa gambling; intertemporal choice; other measures) in 100 patients about to undergo sleep testing. It is expected that of these 100 patients, some will have no sleep apnea; some will have sleep apnea and will be successfully treated; and that some will have sleep apnea but will not be successfully treated by the time of repeat testing. The investigators will repeat testing using the same instruments 2 months later.