For most people, learning to play music is not generally thought of as being second nature like learning to speak a language is. But, a new study, conducted at Duke University’s School of Medicine, found a connection between how the brain guides the way humans learn to speak, and play music.
A team of scientists examined the neural (the nerves and nervous system, including the brain) processes that mice utilize, to ignore their own footsteps—this resulted in new discoveries about how we learn to speak—and play music.
The research study was published in a September 12th, 2018 issue of Nature, International Journal of Science.
Lead study author and assistant professor at New York University’s Center for Neural Science, David Schneider explained, “The ability to ignore one’s own footsteps requires the brain to store and recall memories and to make some pretty stellar computations. These are the building blocks for other, more important sound-generating behaviors, like recognizing the sounds you make when learning how to speak or to play a musical instrument.”
Interestingly, the research was based on the fact that we are usually unaware of the sound of our own footsteps. This phenomenon led to the understanding of a greater observation that the nervous system can observe, acknowledge and then remember the sound of one’s own movements in relation to the environment.
“The capacity to anticipate and discriminate these movement-related sounds from environmental sounds is critical to normal hearing,” Schneider explains. “But how the brain learns to anticipate the sounds resulting from our movements remains largely unknown.”
In the study, an “acoustic virtual reality system” was made for the mice, in which the researchers at Duke were able to control the sounds the mice made while walking on a treadmill. At the same time, the scientists observed the neural activity in the mice. This resulted in the ability of the mice to identify neural circuit mechanisms that were involved in the suppression of movement-related sounds.
The mice in the study were able to filter out sensory input—the sound of their own footsteps—and in turn, this allowed them to more astutely detect sounds coming from their environment.
“For mice, this is really important,” said Schneider. “They are prey animals, so they really need to be able to listen for a cat creeping up on them, even when they’re walking and making noise.”
The researchers surmised that being able to screen out the sounds of one’s own movements is equally important for humans. But, the ability to take it a step further, and anticipate the sounds of our actions is a more complex human behavior that is required for speaking or playing music.
“When we learn to speak or to play music, we predict what sounds we’re going to hear — such as when we prepare to strike keys on a piano — and we compare this to what we actually hear,” explains Schneider. “We use mismatches between expectation and experience to change how we play — and we get better over time because our brain is trying to minimize these errors.”
“Overactive prediction circuits in the brain are thought to lead to the voice-like hallucinations associated with schizophrenia while an inability to learn the consequences of one’s actions could lead to debilitating social paralysis, as in autism,” explains Schneider. “By figuring out how the brain normally makes predictions about self-generated sounds, we open the opportunity for understanding a fascinating ability — predicting the future — and for deepening our understanding of how the brain breaks during disease.”
Nature International Journal of Science