鸟类如何通过模仿来学习技能

Precise changes in brain circuitry occur as young zebra finches go from listening to their fathers' courtship songs to knowing the songs themselves, according to a study led by neuroscientists at NYU Langone Medical Center and published online in a Science cover report on January 14. The study reveals how birds learn songs through observation and practice, and the authors hope the work will guide future research into how patients with brain injuries might reacquire the ability to learn skilled behaviors like speech. 

"While we have known for decades that adolescent songbirds only learn their songs if exposed to a tutor, we believe our study is the first to detail changes in nerve networks that make this mastery possible in maturing brains," says senior study investigator Michael Long, PhD. 

"Our results show that finch song learning reflects a 'dance' inside the brain's vocal control center between nerve cells that capture information as the bird listens and those that direct muscle movement as it sings," says Long, an assistant professor of neuroscience at NYU Langone. 

In the current study, led by Daniela Vallentin, PhD, and Georg Kosche in the NYU Neuroscience Institute, the research team found that early in adolescence, just listening to a father's song turns on the same brain cell networks that the young bird will use later to sing the song once learned.

A second result revolves around a set of nerve cells in the brain - inhibitory interneurons - which dampen the activity of surrounding nerves to sculpt sensory input into function. Researchers found that interneurons suppress the impact of each note in a father's song as soon as it is learned, "locking" it into the younger bird's memory piece by piece. 

"Our research advances the understanding of how skilled behaviors are learned, and the role played by sensory inhibition in making memorized patterns permanent," says Long. Such a framework, he says, could apply to complex behaviors in people, such as dancing or hitting a baseball.