Bird Brains Give Insight into Baby Babble
Scientists who have been searching for insight into how the brain learns motor tasks have had a new breakthrough. By studying the brains of both adult and juvenile songbirds, it has now been realized that there are two completely different brain circuits that are involved in the process.
Up until the new discovery was made, researchers generally thought that vocalization performed at any age is a direct function of the High Vocal Center (HVC). However, researchers Dr Fee, Dmitriy Aronov and Aaron S. Andalman have come to a different conclusion following a series of experiments performed on zebra finches. Their research showed that the HVC did not have any effect on babbling whatsoever, but rather that a different circuit entirely was involved. This circuit is known as the lateral magnocellular nucleus of the nidopallium (LMAN).
During the course of the experiments, the HVC was inactivated in both adult and young birds. When inactivated in the adult birds, the birds ceased singing but continued to vocalize. The sounds they uttered sounded similar to the random sounds made by baby birds. When the HVC in baby birds were deactivated, the baby birds continue to babble as they had previously. This proved that the LMAN circuit was responsible for helping the bird to learn the various vocalizations, while the HVC was responsible for producing that particular vocalization. It was further discovered that if the LMAN was damaged in any way in an immature bird still learning to sing, the bird could not learn to develop its call more fully. However, if an adult bird suffered damage to its LMAN, it would not affect its ability to sing already learned songs.
Scientists hope that the new findings will give insight into the far more complex human brain since there are certain similarities that are shared between a human brain and a bird’s brain. Baby birds seem to babble, much like human babies do, learning to mimic adult birdsong in a similar way to how human babies learn to mimic adult speech. The research shows that this learning pattern, and the final result of speech, is likely linked to two different mechanisms in the brain. More research is still being done to further refine the understanding of these mechanisms.