In the brain, specific electrical waves are associated with different states of consciousness. For instance, delta waves—also known as slow waves—are especially prevalent during deep sleep, as well as during states of unconsciousness induced by coma and general anesthesia. They are considered a “signature” of these altered states of consciousness.

Over a decade ago, research showed that it is possible to amplify these delta waves through highly precise auditory stimulation, a technique initially studied in the context of sleep.

Now researchers at Université de Montréal are bringing this technique into the operating room to help optimize general anesthesia, which also induces a state characterized by abundant delta waves.