Robot exoskeletons improved physical coordination between musicians through transmitted touch, even though none of the participants knew the devices were connecting them, a recent study’s findings reveal.
Of the three senses that humans rely on to coordinate physical movement, sight, sound, and touch, only two are transmittable across a distance. To date, there has never been a way to send the physical sensation of another person’s movement to someone in a different location in real time.
Now, in a study published in the journal Science Robotics, researchers set out to see whether that could change and, if so, whether it would make a difference.
A European Union-funded initiative called CONBOTS (CONnected roBOTS) awarded researchers nearly five million euros to explore the role of touch in human coordination and learning. For the study, forty violinists recruited from Ghent, Belgium, were paired into twenty duos and fitted with a robotic arm brace that tracked their movements and relayed corresponding force signals to their partner in real time.
Each duo performed a custom-composed piece of music in four states, unaware that the devices strapped to their arms were transmitting their movements to their partners in real-time. The states were either sound alone, sound and vision, sound and haptic feedback delivered by the robotic brace, or all three combined.
Haptic feedback, in this context, refers to the physical sensation of touch and force delivered through the exoskeleton. Throughout each performance, researchers were measuring whether the body would pick up and use the physical signals it had no conscious knowledge of receiving.
Of the four states, when tested alone, touch outperformed sight at improving coordination between partners. But the best results came when all three inputs—sight, sound, and touch—were combined.
The findings held across the group, but not equally: professional musicians benefitted more than the amateur musicians, a gap the researchers noted but did not fully explain. The answer likely lies in how a professional violinist’s sensitivity to touch is shaped after years of practice.
Professional violinists develop a specific physical skill over years of practice. This allows them to detect and control tiny differences in bow pressure without having to think about it consciously. The difference between a resonant tone and an unpleasant one is a near imperceptible difference in pressure on the violin strings. This ability is known as proprioception, the body’s internal sense of where it is and what it is doing in space.
When the robotic exoskeleton delivered its signal, professional musicians had the sensory framework to receive it, no matter how subtle. Whereas their amateur counterparts did not, at least not to the same degree.
Researchers say the findings, though early, point to something much more significant. The system could be tested in further experiments and the technology adapted for other applications, changing how physical skills are learned in rehabilitation, motor learning, and athletic training.
For instance, a teacher and a student, or a physical therapist and a patient, could be physically coupled through these exoskeletons, allowing movement corrections to be conveyed directly through touch, regardless of distance. Principal investigator Professor Domenico Formica said the findings suggest robots could serve both as tools and conduits between people. “We are entering an era where robots can mediate physical communication between humans in entirely new ways,” he said.
The study could be tested in further experiments in the coming years. Researchers point to areas such as athletic training, education, and rehabilitation that have not yet been tested in real-world settings.
For now, what the findings offer is early evidence that exoskeletons can introduce a new channel for human communication, one that is embodied, immediate, and largely implicit. Although the study’s findings are intriguing, the question of whether the system works for collaborative tasks beyond violin duo performance remains to be explored.
Marie Nicola is a journalist, pop culture historian, and former CBC Senior Producer whose investigative research explores the intersection of culture, technology, and history. She has contributed to the Globe and Mail, collaborated with Reddit, and been featured in TrendHunter as an early innovator in streaming and digital broadcasting. Follow her on X @karmacakedotca.