Closed Loop Acoustic Stimulation During Sedation With Dexmedetomidine

A non-contrast brain MRI will be acquired for localizing EEG slow waves

Quantitative sensory testing (QST) using increasing ramp thermal stimulation (32-52 ºC) will be delivered to compare arousal thresholds between conditions.

Unattended home sleep studies will be conducted on the night preceding sedation and on the night following sedation to assess changes in slow wave homeostasis.

Acoustic stimulation (65 db) synchronized in-phase with the up-slope of EEG slow waves

65 dB acoustic stimulation synchronized with the down-slope of the EEG slow waves (anti-phase)

sham stimulation (0 dB volume)

All participants will receive dexmedetomidine with sedation titrated step-wise to 2, 3 or 4 ng/ml

All participants will be asked to perform the breathe-squeeze task throughout the experiment. This will allow us to determine loss and return of responsiveness.