Posted March 12, 2018
Have you ever wondered why when you hear music your foot taps to the beat? Or, how your brain fills in conversations at a loud event when you can only catch a few words of what people are saying? Scientists report that understanding the human brain is one of their greatest challenges. However, recent research offers news insights: This is how your brain’s motor system interprets sounds.
Operates like a computer
Scientists compare the brain to a large computer. It receives information from your senses and nerves, processes it and sends messages back throughout the body. However, unlike a machine, the brain also can recognize emotion and movement to impact responses.
Motor system process
The area of the brain that directs movement is called the motor system. It allows you to see with your eyes, touch objects with your hands, or use your legs to walk. These actions assist the brain in making connections to things you already know. But when it comes to hearing, scientists had minimal knowledge about how it works with the motor system, until recently.
Studies explore sound and brain connection
Researchers at the Montreal Neurological Institute at McGill University in Canada studied 21 participants while they listened to complicated tone sequences. They were connected to a machine that recorded brain reactions, and were asked to indicate whether a target melody was at a higher-pitch or lower-pitch than a specific tone. A series of distracting sounds also was played to determine the brain’s ability to focus on the target melody. In one part of the study, the participants were completely still, and in the second part, they tapped the rhythm on a touchpad.
The study revealed that the brain’s motor system anticipated when a sound would occur, and sent this information to the hearing area to interpret the sound. The motor system accurately sent these directions in both parts of the study. However, the scientists discovered that the hand-tapping exercise, in part two, improved brain performance.
Through this study, researchers determined how the brain interprets visual and auditory cues to fill in missing words in conversations, which is especially helpful in loud environments. Scientists discovered that the eyes watch for nonverbal signals, such as lip movement and head tipping, and the ears catch voice pitch and tone. The brain’s motor system then uses this information to complete sentences.
Researchers are doing additional studies to further understand the motor system’s function, with the goal of improving treatment for people who struggle with hearing or speech comprehension.