Washington, May 2 (ANI): Just like human infants, baby birds too babble before they learn how to sing.

The discovery has researchers excited as it sheds new light on how birds, and perhaps people, learn new behaviours.

Researchers
at Massachusetts Institute of Technology have found that immature and
adult birdsongs are driven by two separate brain pathways, rather than
just one pathway that slowly matures.

“The
babbling during song learning exemplifies the ubiquitous exploratory
behaviour that we often call play but that is essential for
trial-and-error learning,” said Michale Fee, the senior author of the
study and a neuroscientist in the McGovern Institute for Brain Research
at MIT and an associate professor in MIT’s Department of Brain and
Cognitive Sciences.

Previous
research had shown the zebra finch has two brain circuits dedicated to
song, one for learning and another - known as the motor circuit - for
producing the learned song.

Damage to the first circuit while the bird is still learning prevents further learning, so the song remains immature.

Yet in an adult that has already learned its song, disabling the learning circuit has no effect on song production.

Scientists
assumed the motor circuit was equally important in producing baby
birds' babbling, but no research had been conducted.

The
new study that included graduate students Dmitriy Aronov and Aaron
Andalman involved temporarily disabling parts of the brain, and record
from neurons in the singing bird.

When
they disabled a part of the motor circuit known as HVC in these very
young birds, the babies continued to sing, implying that some other
brain region produces the babbling.

The researchers suspected a key component of the learning circuit, called LMAN, has a previously unknown motor function.

They confirmed this by showing that when LMAN was disabled, the immature birds ceased babbling.

“This
tells us that singing is driven by two different motor circuits at
different stages of development. We’ve long known that these two
pathways develop physiologically at different times, so there’s an
elegant parallel between our functional findings and what is already
known about anatomy,” Aronov said.

The researchers also found that LMAN retains its ability to drive babbling even in adulthood.

Disrupting
HVC in adults caused the birds to revert immediately to babbling,
suggesting that LMAN can take over again if the more powerful signals
from HVC are blocked.

Fee
speculates that these results may apply more broadly to other forms of
immature or exploratory behaviour, in humans as well as birds.

“In
birds, the exploratory phase ends when learning is complete. But we
humans can always call upon our equivalent of LMAN, the prefrontal
cortex, to be innovative and learn new things,” he said.

The study is published in the May 2 issue of Science. (ANI)