Study Finds Hippocampus Continues Processing Speech and Grammar Under General Anaesthesia

A study published in Nature on May 6 reported that the brains of people under general anaesthesia continue to process words and sounds. The hippocampus remains active under general anaesthesia and parses the grammar and meaning of spoken words while also anticipating what will be said next, according to @Nature reported.

Researchers observed people’s individual neurons firing in real time while under anaesthesia.

Seven people anaesthetized with propofol had their brain activity recorded while undergoing surgery to treat epilepsy. Complex cognition such as grasping semantics and forecasting future events can occur without full consciousness. Previous studies have shown that the parts of the brain that first detect sensory input can still register simple sounds while a person is unconscious.

It had remained unclear whether deeper regions of the brain are capable of complex cognition while someone is unconscious, @Nature reported.