A popular theory linking auditory hallucinations to certain types of illnesses has been disproved by a new study conducted jointly by the École Polytechnique Fédérale de Lausanne (Switzerland) and the Université de Savoie Mont Blanc (France). This study expands the understanding of the origin of auditory hallucinations (HAHs) and shows that they can occur in healthy people.
As part of the research, a new method was developed that included voice perception and sensorimotor stimulation. 48 people participated in the experiment. In the course of the experiment, the participants' hearing was influenced by a mixture of pink noise, reminiscent of the sound of a waterfall, and fragments of voices, both familiar and unfamiliar to them. At the same time, the participants felt the sensorimotor stimulation caused by pressing the button and the subsequent kicks of the robot.
The results of the study showed that the participants of the experiment not only felt a presence behind them, associated with the movement of the robot, but also heard voices that were not present in the external auditory stimuli. This finding suggests that auditory hallucinations can occur under certain conditions in the brain.
Interestingly, hallucinations were more likely if participants heard an unfamiliar voice before a familiar one and if there was a delay between the button press and the sensorimotor stimulation. These results suggest that hallucinations may be caused by a deficit in the ability to monitor and distinguish the self from the world around us, as well as by the influence of strong prior beliefs or assumptions on perception.
This study challenges the common belief that auditory hallucinations are unique to neurological disorders such as schizophrenia. Instead, it cautions against generalizations and emphasizes that hallucinations can occur in healthy people under certain conditions.
These results may be important for understanding the mechanisms of auditory hallucinations and their relationship with various diseases, including Parkinson's disease. The study also helps to demystify this phenomenon, warning those who may encounter it in the future.
