Spectral entropy has been used to guage the depth of anesthesia in surgery. The definition of Spectral entropy is the log of the number of available cortical microstates. As entropy decreases the level of consciousness decreases. An increase in entropy might be inferred to indicate an increased level of consciousness.

A brief overview of research on cortical microstates will be presented. A method of utilizing a measure of spectral entropy in neurofeedback and assessment will be examined.