For centuries, lullabies have been used by various cultures around the world to pass down cultural knowledge and tradition, but most importantly they facilitate a nurturing relationship between caregiver and child. They have been seen to develop infants’ communication skills, attentive awareness, modulate arousal, and regulate behavior. Traditionally, lullabies have been sung with simple melodic lines that make use of repetitive themes and consonant intervals. So why do they work? And if so, how? A recent study published by Laurel Trainor, Christine Tsang, and Vivian Cheung, from McMaster University, has proven the long-held notion that infants do in fact prefer consonant intervals (calm and agreeable) more so than dissonant ones (which build up tension and desire for consonant intervals).
Preliminary studies have also shown how continuous exposure to music from a parent or caregiver has taught infants how to remember simple melodies over a period of several weeks, distinguish metrical structures, and even integrate movement and auditory information from some of the more complex meters. In order to further understand how music nurtures an infant’s ability to process information, we must understand the rapidly changing neurological environment present in the brains of newborns. It is by recognizing the incredibly malleable structure of a baby’s developing brain that allows us to successfully present music to infants and babies in ways that may facilitate the growth of healthy cognitive and behavioral skills.
Babies are born with about 100 billion neurons, the amount they will have for the rest of their lives, with each neuron containing about 2,500 synapses. By the age of 3, each neuron of a baby’s brain has about 15,000 synapses and continues to grow, creating trillions and trillions of connections (much more than they will need in adulthood). But by having many more synapses than is needed, along with a low amount of inhibitory neurotransmitters, an infant’s perception of reality is much less focused than an adult’s. Similar to how a lantern’s light scatters and touches everything in a surrounding room, a baby’s attention is broad and nonselective. This allows stimuli in the environment — any music, movement, or smells — to initiate a process within the brain called pruning. As an infant’s brain learns about the environment, pruning begins to strategically shape and rewire particular neuronal networks while discarding the ones it sees as unimportant. An easy way to observe this process of pruning is by noticing how a baby gradually singles out particular stimuli over time. When babies learn how to attend to certain stimuli, such as their mother’s voice, they may make a sound, like some type of babble, to convey their interest.