Although many poets believe rhythm cannot be separated from language, scientists have been less certain about the connection between the two. In particular, they have wondered about the different ways in which the brain responds to each. Now, a study conducted at Northwestern University provides evidence that people who perform better on rhythmic tests also show ‘enhanced neural responses’ to speech sounds.
Motor Task And Neural Response
The researchers asked more than 100 teenagers to tap their fingers along to a beat while they measured their accuracy with a metronome. "It turns out that kids who are poor readers have a lot of difficulty doing this motor task and following the beat," Nina Kraus, of the Auditory Neuroscience Laboratory at Northwestern University, told BBC News.
Then, in order to understand the neurological basis of the ability to tap out a rhythm, the research team measured and recorded the brain waves of participants with electrodes, a technique known as electroencephalography. By this method, they were able to observe the electrical activity in the brain in response to sound. What they found may seem unsurprising to poets: The researchers discovered that the recorded brain waves matched the sound waves. Specifically, those participants who demonstrated less variability when tapping to a beat also showed auditory brainstem responses that were less variable.
“You can even take the recorded brainwave and play it back through your speaker and it will sound like the soundwave,” Kraus told BBC News.
The responsive brainstem area that she and her colleagues closely observed is the inferior colliculus (IC), a mass of nerves that forms the greater part of the back of the midbrain. The nerves within the IC function as an auditory center that scientists believe may participate in the integration of hearing reflexes. Because the IC is directly connected to subcortical motor structures, the researchers hypothesized that consistency of the neural response to sound within the IC may be linked to the ability to tap consistently to a beat.
“It seems that the same ingredients that are important for reading are strengthened with musical experience. Musicians have highly consistent auditory-neural responses,” Kraus told BBC News. She hypothesized that musical training may exercise the auditory system and so lead to a stronger sense of sound-to-meaning associations that are essential to reading.
The researchers suggest that practicing music could improve other skills, particularly speech. “In both speech and music, rhythm provides a temporal map with signposts to the most likely locations of meaningful input,” Kraus told BBC News.
Source: Tierney A, Kraus N. The Ability to Move to a Beat Is Linked to the Consistency of Neural Responses to Sound. The Journal of Neuroscience. 2013.