Study explains reasons why schizophrenic patients hear voices

People with schizophrenia often hear voices that do not exist in the real world. For years, scientists have tried to crack the code to auditory hallucinations. In a recent study led by Chen Zhang, Shanghai Jiao Tong University School of Medicine and Xing Tian, New York University Shanghai, researchers have finally concluded that hearing voices is a result of the brain’s impairment in processing and predicting sensory information.

Why auditory hallucinations happen?
For years, auditory hallucinations were believed to be a product of overactive imagination – which is rampant in schizophrenia. However, the recent study quashes that myth and explains that it is indeed a biological process that involves a complicated interplay between the motor and sensory systems in the brain.

The study was conducted on two groups of schizophrenic patients – one group who experienced auditory verbal hallucinations, and the other group that did not. Studying their differences in brain function, the researchers concluded the result.

During the study, the participants were put into different scenarios where they were asked to speak – which one situation involved them speaking while being prepared, the situation asked them to speak without knowing what. In these situations, the researchers played sounds and measured the responses of the brain using electroencephalography.

Brain’s impairment in motor planning and prediction
It was observed that in healthy individuals, general speech preparation could suppress overall auditory responses, which in schizophrenic patients that was not the case. Hence, a fundamental impairment in this inhibitory mechanism was revealed by the study.

This study serves as a wake-up call to explore better treatment options for schizophrenia and other mental disorders. It also helps us identify that often what is thought as a sensory phenomenon may have deep-rooted explanations in the brain’s procedure of planning and predicting mechanisms. In certain forms of dementia or drug-induced states, the perception of reality is altered, much like schizophrenia – this study can help in understanding the mental conditions and provide treatment options.