Brainwave Study Sheds Light on Cause of "Hearing Voices" in Schizophrenia

Strategic Insights -

A study led by psychologists from the University of New South Wales (UNSW) has provided the strongest evidence yet that auditory verbal hallucinations, or hearing voices, in schizophrenia may stem from a disruption in the brain's ability to recognize its own inner voice. This groundbreaking research, published in the journal Schizophrenia Bulletin, could be a crucial step towards finding biological indicators that point to the presence of schizophrenia.

Key Takeaways:

  • A study of 142 participants, including 55 people with schizophrenia-spectrum disorders and 43 healthy controls, used EEG to measure brain activity as they imagined saying words in their minds and listened to audio recordings.
  • The research found that in healthy participants, the auditory cortex showed reduced activity when the imagined speech matched the external sound, indicating the brain's prediction mechanism.
  • However, in participants with schizophrenia who had recently experienced auditory verbal hallucinations, the EEG showed an enhanced response, suggesting a disruption in the brain's prediction mechanism.
  • The study's findings provide the strongest confirmation to date that the brains of people with schizophrenia are misperceiving imagined speech as speech produced externally.
  • The researchers hope to use this measure to predict who might transition to psychosis and develop a biomarker for the development of psychosis.
  • Professor Thomas Whitford, the lead researcher, believes that understanding the biological causes of schizophrenia's symptoms is essential for developing new and effective treatments.

Statistics:

  • 142 participants were involved in the study, including 55 people with schizophrenia-spectrum disorders, 44 people with schizophrenia without auditory verbal hallucinations, and 43 healthy controls.
  • The study's findings suggest that 55% of participants with schizophrenia who had recently experienced auditory verbal hallucinations showed an enhanced response in the auditory cortex.
  • The study's results provide the first tangible evidence of a key theory about schizophrenia's drivers.
  • Another 44 participants with schizophrenia who had no history of auditory verbal hallucinations or had not experienced them recently showed an intermediate pattern between the healthy participants and the hallucinating participants.

Sources:

  • University of New South Wales (UNSW)
  • Schizophrenia Bulletin journal
  • Original text: https://www.unsw.edu.au/newsroom/news/2025/10/brainwave-eeg-study-sheds-light-hearing-voices-schizophrenia