When you hear your favorite song, you probably can’t help but tap your foot or nod your head to the beat.
This ability to predict and synchronize with rhythmic sounds is something most humans do naturally – it underlies music, dance, and even the rhythm of conversation. But scientists have long debated whether this ability is uniquely human or whether other animals have the same capacity hidden in their brains. Our research suggests that monkeys do have the brain machinery for rhythm – it’s just “switched off” until the right motivational trigger activates it. In our preliminary experiments, we recorded brain activity while a monkey listened to repeating tone patterns. At first, the motor areas of the brain ignored the tones completely. But when we paired each tone with a small juice reward, something remarkable happened: brain regions involved in movement and motivation suddenly “woke up” and began tracking the rhythm. Even more surprising, this new brain pattern persisted after we stopped giving rewards – as if the tones themselves had become meaningful.
In this project, we will follow the full journey of learning: from a naive animal that ignores rhythmic sounds, to one that anticipates them and times its movements to match. We will record from multiple brain areas simultaneously as the animal learns, allowing us to see exactly where and when rhythmtracking signals first appear and how they spread through the brain. Understanding how the brain learns to predict and synchronize with sounds could help us develop better treatments for conditions like Parkinson’s disease, where patients struggle with movement timing, and autism, where rhythm processing is often impaired. Our findings may also explain why music therapy can be so effective and guide the development of new rehabilitation approaches.
