THURSDAY, June 2, 2005 (HealthDay News) -- The hand that rocks the cradle may also trigger a lifelong love of music, rhythm and dance, a new Canadian study finds.
Research involving moms cuddling and bouncing happy 7-month-olds suggests their shared attraction to music may be based on much more than the sound that enters their ears.
"Our findings provide evidence that the experience of body movement plays an important role in musical rhythm perception," concluded researchers Laurel Trainor, a professor in the department of psychology at McMaster University, in Hamilton, Ontario, and graduate student Jessica Phillips-Silver.
While it may seem like child's play, the study -- published in the June 3 issue of Science -- brings intriguing new insights into how the brain simultaneously uses multiple sensory systems to tune into music.
"Up till now, all studies of music have really just studied the auditory system," Trainor explained. "But if you think about where music came from, its evolution and how we practice it and move to it -- how we like to actually go to a concert and see musicians performing -- clearly, there are other systems involved."
And those systems may start coordinating from the very beginning of life, the researchers believe.
In their study, Trainor and Phillips-Silver had mother-infant pairs listen to a simple two-minute piece of music with a rather ambiguous rhythm.
Some mothers were instructed to bounce their babies in a kind of "military march" time (ONE-two-ONE-two-ONE), while others bounced their tot in waltz time (ONE-two-three-ONE-two-three).
The music was then replayed with special rhythmic accents to mark it as either a march or waltz. The researchers watched closely to see which version each baby would prefer.
Because 7-month-old infants can't verbalize their preferences, the researchers relied on a simple technique: When a baby looked at a specific light, the researchers turned on the "march" piece. But if they looked at a second light, the "waltz" music started to play.
Trainor and Phillips-Silver found that babies whose moms had rocked and bounced them to the march beat strongly preferred that version of the melody. On the other hand, infants who first heard melody while being waltzed in their mother's arms preferred that version of the song.
In a third experiment, the researchers had the babies listen to the music while simply watching their moms move to the beat -- without being rocked or held.
Those babies showed no preference for either the march or the waltz, suggesting to the researchers that "the movement of the infant's own body was critical" to his or her response to music.
All of these findings suggest babies "are getting concurrent sound and movement experience" that influences their perception of rhythm and music, Trainor said. She believes a whole array of neurological systems -- auditory, visual, proprioceptive (the body's sense of itself) and vestibular (movement and balance) -- are working in harmony to help humans process and enjoy the musical experience.
"I think we're wired for it," said Alice Sterling Honig, a professor of psychology at Syracuse University, and an expert in both early child development and music. "All our senses are able to be wired into the motor center and other centers in the brain, and that wiring goes on from the moment the nervous system starts to send those wonderful impulses down those pathways."
She and Trainor also pointed out that a love of rhythmic music -- including baby-rocking and lullaby -- is innate to all known human cultures.
"In our past work, we've shown that mothers across cultures will sing to their babies, and babies are very responsive to song, very early on," Trainor added. "But in doing these studies, one of the things that always struck us was that as mothers are interacting with their infants they are always moving them, rocking them, bouncing them."
"If that's true, the brain should really be wiring itself up according to the experience that it's getting," she said.
But why are humans unique among species in their love of music?
"Other animals have vocalizations but as far as we know, no other animas have either music or language," Trainor said. "One answer might be that, for humans, music serves a social-emotional function. Certainly if you look at a mother singing and rocking an infant, there's a clear emotional exchange going on there."
She said the study leaves unanswered the question of whether a love of music is hard-wired or learned. Trainor believes both may be true.
"Certainly without the experience of music you won't develop an appreciation for it," she said. "But you also have to have this brain structure that is already wired up to respond to that stimulation. You need both."
For more on music and the human mind, head to the American Psychological Association.