Words like music to the ears

By Marie Rogers

Infants are born into a big, confusing world of sights and sounds: there is a huge amount of information to process. In order to deal with this, the brain must learn to prioritise certain information over others. This process is known as ‘plasticity’ and the brain is most plastic during development.

Plasticity plays an important role in acquiring language during childhood. The first challenge an infant must overcome in order to learn their native tongue is to fragment speech into meaningful sounds.

If you have ever tried to learn a completely new language, you might have found it difficult to hear where one word ends and the next begins. During development, an infant learns this by becoming “tuned” to familiar sounds in the language(s) surrounding them. However, this also can also mean losing some distinctions, for example Japanese speakers often find it difficult to distinguish between “r” and “l” sounds in English. This is because this distinction isn’t made in Japanese, so they did not learn to recognise it during development.

Music picture Michael Hoefner

Recent evidence shows that a similar process of familiarisation during development may occur with music too. Western music is based on pentatonic scales, consisting of five tones, which we are probably all familiar with. People who have grown up around this type of music can generally point out a discordant note in a piece following the ‘rules’ of Western music. However, music from other cultures may sound strange or even unmelodic to people unfamiliar with it. The music scales of Indonesia, for example, are based on the sounds of the xylophone.

One recent study investigated how children become tuned to their native music over the course of their development. The authors asked four and five year old children to identify the discordant piece of music from a selection. They found that the five year olds were generally able to complete the task, but the four years olds could not. However, when they measured the electrical activity of the brain during the task, they found that the younger children showed brain responses characteristic of being sensitive to discordancy. This demonstrates that although the four year olds could not behaviourally demonstrate their knowledge of harmony, their brain nevertheless responded differently to harmonic versus disharmonic music.

These results are fascinating because they may tell us something about the evolutionary history of language. One theory suggests that music predated language in our evolution, and that it may have been, in our past, the main method of communication. The finding that music and language development are very similar may further support the theory that language evolved using the pre-existing neural mechanisms of music.