What happens to your brain when you are under general anesthesia? Dr. Emery Brown explains that under general anesthesia your brain is not turned off but is very dynamic. Electrical oscillations in the brain can be recorded using an electroencephalogram (EEG).  Brown shows how oscillations induced by anesthesia interfere with normal communication between different regions of the brain. By following oscillations of different frequencies, it is possible to monitor and adjust a patient’s level of unconsciousness under anesthesia.