Are the voices in the heads of schizophrenics real?

A new study has proven a half-century-old hypothesis: the 'voices' people with schizophrenia hear actually originate from their own inner speech, but the brain mistakes them for sounds coming from outside.

Most patients with schizophrenia say they hear a voice constantly in their heads - Photo: AI

For the past 50 years, scientists have suspected that auditory hallucinations (hearing voices that aren't there) in schizophrenia patients are caused by the brain confusing "inner voices" with real sounds from the environment. However, because inner speech is a private experience, proving this has been nearly impossible, until now.

Thomas Whitford, a psychology researcher at the University of New South Wales (Australia), and colleagues used electroencephalography (EEG) to measure brain waves when participants "spoke in their heads", and compared that response with when they heard voices in hallucinations.

"When we speak, even just silently in our heads, the brain's processing of external sounds is weakened, because the brain has 'predicted' our own voice. But in people who hear 'voices,' that prediction process goes wrong. The brain reacts as if the sound is coming from someone else," Whitford explains.

According to ScienceAlert, the research team conducted a test on 142 people, divided into three groups: 55 people with schizophrenia who had recent auditory hallucinations, 44 people with the disease but without auditory hallucinations, and 43 healthy people with no history of mental disorders.

All were asked to listen to the sound through headphones and imagine silently saying the word "bah" or "bih" in their heads at the same time as the sound was played. They had no idea whether the sound they heard matched the word they were thinking.

The results showed that in the group with auditory hallucinations, when the "inner speech" matched the external sound, the brain reacted much more strongly than in the other two groups.

“In normal people, when we speak silently in our heads, the brain region that processes sound decreases in activity, just as it does when we hear our own voice,” explains researcher Thomas Whitford. “But in people who regularly hear ‘voices,’ this response is reversed: the same brain region becomes more active, as if they were actually hearing someone else’s voice.”

This finding strongly supports the hypothesis that the voices heard by schizophrenic patients are their own inner voices, but the brain misinterprets the source of the sound, thinking it comes from outside.

This could open up new avenues for early diagnosis and early intervention for people at risk of psychosis, before severe symptoms appear.

This research not only helps to decode one of the oldest mysteries in psychiatry, but also contributes to reducing stigma against the patient, showing that the "voices" they hear are not baseless imagination, but the result of a biological deviation in brain activity.

The work was published in the journal Schizophrenia Bulletin, October 2025.

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MINH HAI

Source: https://tuoitre.vn/giong-noi-trong-dau-nguoi-tam-than-phan-liet-co-that-khong-20251026215716943.htm