In this proposal the investigators seek to determine whether sedation mediated by activation of α2 adrenoceptors (dexmedetomidine) is more like natural sleep than that provided by a sedative agent that modulates the GABAA receptor (propofol), two common widely used sedative agents in ICU. Ten volunteers will be enrolled and each subject will be studied on three experimental sessions. Subjects will be randomized to receive a continuous infusion of either saline, dexmedetomidine (DEX), or propofol in each of the three sessions. By relying on clinical rating scales, the investigators ensure that the doses of DEX and propofol administered induce equisedative states before progressing to magnetoencephalography and electroencephalography data collection.