A robot can make us hear sounds that don’t exist

If you think hearing voices is a phenomenon limited to those with mental disorders, you may need to rethink your beliefs. A recent study used robots to make healthy people hear voices, shedding new light on the brain mechanisms responsible for 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 Orbec From the University of Geneva, we have a new way to explore the mystery of the human mind. Using a robot, scientists have been able to induce hallucinations in healthy individuals, offering a new perspective on how our brains can sometimes fool us.

Method: Between robotics and psychology

The research team used an innovative method to induce hallucinations in participants. The researchers recorded the participants’ voices speaking 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 the sound detection task. Let’s try to understand each other simply (if you still want to refer to the full study, there he is).

Induction of “false” sounds in the mind: stages of experience

Stage 1: Touch the robot

Participants were blindfolded and the robot touched them on their backs while moving their finger. Sometimes the touch was in sync with the movement, other times there was a slight delay.

The second stage: hearing test

Participants heard background noise and had to say whether they heard a sound or not. This helped to understand how sensitive their hearing is.

Stage 3: Touch and hearing together

Here, participants performed a hearing test while the robot continued to touch their backs. The idea was to see if the robot’s touch disoriented them enough to make them hear sounds that weren’t there.

Evoked sounds: effects

The results showed that the timing of sensorimotor stimulation played a crucial role. When back-tapping was synchronized with finger movements, participants reported significantly more false alarms, indicating the perception of hearing sounds that were not actually there. This suggests a fascinating link between sensory feedback from a person’s actions and the creation of auditory hallucinations.

Limitations and future prospects

Although innovative, the study has limitations. First, the sample size is relatively small and participants were selected from the general population. Future studies would benefit from larger and more diverse samples, including individuals with diagnosed psychiatric conditions.

For now, however, the study represents an important 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 psychological disorders. In these cases, every step forward is a step toward hope.