How sound—but not touch—shapes rhythm in the brain

How do people keep the beat to music? When people listen to songs, slow waves of activity in the brain correspond to the perceived beat so that they can tap their feet, nod their heads, or dance along.

In a new JNeurosci paper, researchers led by Cédric Lenoir, from Université catholique de Louvain (UCLouvain), explored whether this ability is unique to hearing or whether it also happens when rhythm is delivered by touch.

The researchers recorded brain activity as study volunteers finger tapped to the beat of music delivered via sound or rhythmic vibration. With sound, the brain generated slow rhythmic fluctuations that matched the perceived beat, and people tapped along to the rhythm more steadily.

However, with touch, the brain mainly tracked each burst of vibrations one by one, without creating the same beat-like fluctuations, and people were less precise in the way they synchronized with the rhythm.

Says Lenoir, “The ability to move in time with a beat is essential for human social interactions through music. Future research will help clarify whether long-term music practice can strengthen the brain’s ability to process rhythm through other senses, or whether sensory loss, such as hearing impairment, might allow the sense of touch to take over part of this function.”