Resting-state EEG in schizophrenia: auditory verbal hallucinations are related to shortening of specific microstates.

ABSTRACT

OBJECTIVE: Abnormal perceptions and cognitions in schizophrenia might be related to abnormal resting states of the brain. Previous research found that a specific class (class D) of sub-second electroencephalography (EEG) microstates was shortened in schizophrenia. This shortening correlated with positive symptoms. We questioned if this reflected positive psychotic traits or present psychopathology. METHODS: Resting-state EEGs of frequently hallucinating patients, indicating on- and offset of hallucinations by button press, were analyzed. Microstate class D duration was related to spontaneous within-subject fluctuations of auditory hallucinations. RESULTS: Microstate D was significantly shorter in periods with hallucinations. CONCLUSIONS: Microstates of class D resemble topographies associated with error monitoring. Its premature termination may facilitate the misattribution of self-generated inner speech to external sources during hallucinations. SIGNIFICANCE: These results suggest that microstate D represents a biological state marker for hallucinatory experiences.