Impaired functional connections between the brain’s motor and auditory systems could be the reason why some people with schizophrenia suffer auditory hallucinations.according to a study published this Thursday in the journal Plos One.
Patients with certain mental disorders, including schizophrenia, often hear internal voices in the absence of sound, leading them to not distinguish between their own thoughts and external voices.
This disorder implies that the patient has difficulty recognizing his or her own thoughtsand it reduces your independence to take care of yourself or work, among others.
To reveal the root of these auditory hallucinations, a group of researchers from Chinese universities have performed brain scans on schizophrenia patients who hear voices and others who do not suffer from this disorder.
The scientists did electroencephalograms (a test that measures the electrical activity of the brain) to 20 patients diagnosed with schizophrenia with auditory hallucinations and another 20 with the same disease who had never experienced such hallucinations.
The study of the brain waves of the electroencephalograms performed on these 40 patients revealed that Those who suffer auditory hallucinations have failures in the functional connections between the motor and auditory systems of the brain.
On the one hand, they have observed that the brain of people who suffer from these hallucinations does not suppress the internal sound of their own voice when they want to speak, that is, a signal known as “corollary discharge” fails that cancels the internal voice when trying to speak and which works correctly in people who do not hear voices.
At the same time have seen another process in which abnormalities occur: when patients with auditory hallucinations prepare to pronounce a syllabletheir brains not only do not suppress these internal sounds, but they present a greater internal reverberation of the syllable they plan to say.
Along these lines, they conclude that auditory hallucinations would be the result of anomalies in two brain processes: a broken “corollary discharge” that fails to suppress self-generated sounds, and a “noisy reference copy” that causes the brain to hear sounds with more intensity than it should.
Deficiencies in these two processes would contribute to auditory hallucinations, and the authors propose further study to find new treatments, he indicates.