In tone languages, a single word can differ in meaning depending on pitch patterns called "tones." For example, the Mandarin word "mi" delivered in a level tone means "to squint," in a rising tone means "to bewilder," and in a dipping (falling then rising) tone means "rice." English, on the other hand, only uses pitch to reflect intonation (as when rising pitch is used in questions).
As the subjects watched the movie, the researchers used electrophysiological methods to measure and graph the accuracy of their brainstem ability to track the three differently pitched "mi" sounds.
"Even with their attention focused on the movie and though the sounds had no linguistic or musical meaning for them, we found our musically trained subjects were far better at tracking the three different tones than the non-musicians," says Wong, director of Northwestern’s Speech Research Laboratory and assistant professor of communication sciences and disorders.
The research by co-authors Wong, Kraus, Erika Skoe, Nicole Russo and Tasha Dees represents a new way of defining the relationship between the brainstem -- a lower order brain structure thought to be unchangeable and uninvolved in complex processing -- and the neocortex, a higher order brain structure associated with music, language and other complex processing.
These findings are in line with previous studies by Wong and his group suggesting that musical experience can improve one’s ability to learn tone languages in adulthood and level of musical experience plays a role in the degree of activation in the auditory cortex. Wong also is a faculty member in Northwestern’s Interdepartmental Neuroscience Program.
The findings also are consistent with studies by Kraus and her research team that have revealed anomalies in brainstem s