Music synchronized to internal rhythms may provide better pain relief

A melody whose rhythm closely matches our brain’s natural rhythm seems to relieve pain more effectively than a less well-synchronized melody, according to studies conducted by McGill University.

The pain relief associated with listening to music probably stems from the fact that the musical signal “distracts” the brain from the painful signal, said the paper’s co-lead author, Mathieu Roy, who is an associate professor in McGill’s Department of Psychology.

“We can therefore think, hypothetically, that if the music is close to our spontaneous production rhythm, the rhythms associated with the music will take over more from the rhythms associated with the pain,” he explained.

Previous research has shown that when we speak, sing, or play an instrument, we tap into a rhythm of our own: one to which we are more sensitive and which we produce instinctively.

This rhythm — the spontaneous motor tempo, or spontaneous rate of production — is thought to be a distant cousin of the better-known circadian rhythms.

Roy and his colleagues exposed around 60 participants (some of them musicians) to low-intensity pain while listening to music whose tempo had been altered to match their natural rhythm, or whose tempo was slightly slower or faster.

They then assessed the participants’ evaluations of the pain they had experienced. Participants’ internal tempo was also measured by asking them to beat time to a children’s nursery rhyme on a touchpad.

“If you ask someone to produce music … but don’t tell them what rhythm to produce it to, everyone will use their own rhythm,” explained Roy. “Some are going to be a little faster, others a little slower, so that’s the concept we used to calibrate the rhythm of the music we presented to our participants.”

This internal rhythm would be generated by neural circuits that “discharge at a certain frequency,” he added. These are the same “oscillators” that enable our nervous system to perceive the passage of time.

The team found that, compared to silence, music significantly reduced the perception of pain, regardless of style or tempo. This is in line with several other studies already published on the subject.

However, researchers also made a major discovery: the greatest reduction in pain occurred when the melody was played according to the participant’s natural rhythm.

When we listen to music or any stimulus that is rhythmic, over time, our brain activity will be drawn towards this external rhythm.

“Our brain activity will synchronize with this external rhythm,” he explained. “We think that when this rhythm is close to our natural rhythms, it will be easier for the brain to synchronize with the external rhythm. It’s a very general principle of physics: when two oscillators are coupled, they will eventually tend to synchronize their rhythms.

“In this case, we think it’s the brain rhythms that will synchronize more easily to the rhythm of the music, when the rhythm of the music is already close to the brain’s natural rhythms.”

The data from the new study could encourage the integration of music into health care when it comes to fighting pain, he hopes.

“It’s estimated that 20 per cent of the Canadian population lives with chronic pain,” concluded Roy. “And in the face of the opioid crisis, which is very significant, we need to find alternatives. Music is pleasant to listen to, it’s not expensive and there are no side effects.”

The findings are published in the medical Journal of Pain.

–This report by La Presse Canadienne was translated by CityNews