for National Geographic News
North American infants are more adept than adults at recognizing complex musical rhythms, according to a recent study. The findings suggest that the ability to discern irregular rhythms could be "unlearned" in cultures that emphasize more simple musical structures.
"Our findings suggest that throughout our lives, as we passively experience ambient music and as we actively listen to it, we actually shape and tune our perceptual processes in a manner that is specific to the music of our culture," said Erin E. Hannon, the study's co-author. Hannon is a psychology doctoral candidate at Cornell University in Ithaca, New York.
North American adults are not "rhythm challenged," the study says. They have plenty of rhythm, but they are accustomed to more regular meter, the music's underlying beat.
In Hannon's test, 50 North American college students and 17 first- or second-generation Bulgarian and Macedonian immigrants listened to Serbian and Bulgarian folk-dance songs. Two tunes had a simple, Western-style meter. Two other songs had a more complex meter that is uncommon in Western music.
The eastern Europeans were able to comprehend the more complex rhythms, though North Americans struggled to do so. Both groups were able to perceive simple beat structures.
"What you find in almost all the world's music is that at some level, there is a regular beat," said Edward Large, who studies the neuroscience and psychology of rhythm at Florida Atlantic University's Center for Complex Systems and Brain Sciences in Boca Raton.
"Music might have a relatively complicated pattern of timing. But you still hear a basic, underlying beatthat framework that formulates the rhythm," Large said. "We [Westerners] have a very strong bias toward hearing periodic regularity. Some say we actively try to impose [that regularity] on an incoming rhythm."
Music with irregular rhythms often includes another more regular beat. Such complex tunes are found in India and Africa as well as in Bulgaria and other European countries.
In the study, researchers also tested 64 infants aged six to seven months. Much like the adult group of first- and second-generation Bulgarians and Macedonian immigrants, the infants could distinguish between changes in both simple and complex meters.
Infants, with their limited musical exposure, may lack the cultural biases that adults have learned and thus respond to both familiar and foreign musical rhythms.
"This has also been observed in speech perception, and it suggests that infants start out with general abilities that are modified with exposure to language and music," Hannon, the study co-author, said.