The purpose of this study is to see if mental functions take place during different levels of anesthesia using two commonly used drug (propofol and dexmedetomidine) and will include low-intensity focused ultrasound pulsation (LIFUP) to stimulate specific areas of the brain while undergoing functional Magnetic Resonance Imaging (fMRI or "brain imaging"), which shows areas in the brain involved in thinking at different depths of anesthesia. That is, ultrasound is being used to stimulate the brain and multiple pictures will be taken of the brain.
As a result of this study, we expect to gain a deeper understanding of mental function during different levels of anesthesia, and to evaluate if the use of ultrasonic brain stimulation accelerates return to consciousness.