If you think that hearing voices is a phenomenon limited to those suffering from mental disorders, you may need to rethink your beliefs. A recent study used robotics to make healthy people hear voices, shedding new light on the brain mechanisms behind auditory hallucinations.
The discovery that changes everything
Until recently, science had few tools to study auditory hallucinations, a phenomenon often associated with psychiatric conditions such as schizophrenia. But now, thanks to a team of researchers led by Pavo Orepic from the University of Geneva, we have a new way to explore this puzzle of the human mind. Using a robot, scientists have managed to induce hallucinations in healthy individuals, offering a new perspective on how our brains can sometimes deceive us.
The method: between robotics and psychology
The research team used an ingenious approach to stimulate hallucinations in participants. The researchers recorded participants' voices as they spoke single-syllable French words with negative connotations.
These recordings were then standardized for sound intensity and duration, creating a set of speech stimuli that was used in a voice detection task. Let's try to understand each other simply (if you still want to consult the complete study, here it is).
Inducing "fake" voices in the mind: the phases of the experiment
Phase 1: Robot Touch
Participants were blindfolded and a robot touched them on the back while they moved a finger. Sometimes the touch was synchronous with the movement, other times there was a small delay.
Phase 2: Hearing Test
Participants listened to background noise and had to say whether they heard a voice or not. This helped understand how sensitive their hearing was.
Phase 3: Touch and Hearing Together
Here, participants took the hearing test while the robot continued to touch them on the back. The idea was to see if the robot's touch confused them enough to make them hear voices that weren't there.
Induced voices: the implications
The results showed that the timing of sensorimotor stimulation played a crucial role. When the tap on the back was synchronous with the finger movements, participants reported significantly more false alarms, indicating the perception of hearing voices that weren't actually there. This suggests a fascinating link between sensory feedback from one's actions and the creation of auditory hallucinations.
Limitations and future prospects
Despite the innovation, the study has limitations. First, the sample size is relatively small and the participants were drawn from the general population. Future studies may benefit from larger and more diverse samples, including individuals with diagnosed psychiatric conditions.
At the moment, in any case, the study represents a significant step forward in understanding auditory hallucinations. Not only does it help us better understand the brain mechanisms behind this phenomenon, but it also opens the door to new treatment methods for those suffering from psychiatric disorders. And in these cases, every step forward is a step towards hope.
