Schizophrenia is one of the most serious types of mental illness.
Up to 80 percent of people with schizophrenia hear voices that are not really there.
Schizophrenia is one of the most serious types of mental illness.
It can cause delusions, hallucinations, confused thinking and dramatic changes in behaviour.
Patients report that hearing voices is one of the most distressing symptoms of schizophrenia.
The voices, which sound very real to the sufferer, are typically highly distracting.
They are sometimes telling the person to harm themselves or perform other disagreeable acts.
A scrambled auditory cortex
A study has used high-resolution brain scanning to probe the source of the voices in the auditory cortex.
Professor Sophia Frangou, study co-author, said:
“Since auditory hallucinations feel like real voices, we wanted to test whether patients with such experiences have abnormalities in the auditory cortex, which is the part of the brain that processes real sounds from the external environment.”
The research compared 16 people with schizophrenia to 22 healthy controls.
All listened to a range of tones to stimulate the auditory cortex.
This created a ‘tonotopic’ map, which represents how sounds are arranged in the brain spatially.
Imagine a kind of piano keyboard in the brain — the auditory cortex is something like this, with areas representing each different ‘note’ or range of frequencies.
The results showed that the auditory cortex of people with schizophrenia was more sensitive to sounds and was also more ‘scrambled’.
Professor Frangou said:
“Because the tonotopic map is established when people are still infants and remains stable throughout life, our study findings suggest that the vulnerability to develop “voices” is linked a deviance in the organization of the auditory system that occurs during infancy and precedes speech development and the onset of psychotic symptoms by many years.
This is particularly exciting because it means that it might be possible to identify potential vulnerable individuals, such as the offspring of schizophrenia patients, very early on.”
The study was published in the journal npj Schizophrenia (Doucet et al., 2019).
