The investigators are attempting to demonstrate a decrease in the frequency and severity of sedation-induced respiratory arrhythmias(central and obstructive apneas) with pharmacological pre-treatment in this pilot project and then eventually to understand the mechanisms behind this decrease. The efficacy and mechanisms of these treatments, while evaluated during sleep in Obstructed Sleep Apnea (OSA) patients, have not been systematically studied during sedation in either normal subjects or OSA patients. The agent to be assessed in this study in physostigmine versus placebo.