NEW DELHI: A long lasting mystery – how can parrots 'talk' like humans – seems to be heading to a solution at last. An international team of scientists led by Duke University researchers has found that parrot brains are different. This may explain the birds' unparalleled ability to imitate sounds and human speech "This finding opens up a huge avenue of research in parrots, in trying to understand how parrots are processing the information necessary to copy novel sounds and what are the mechanisms that underlie imitation of human speech sounds," said Mukta Chakraborty, a post-doctoral researcher in the lab of Erich Jarvis, an associate professor of neurobiology at Duke and a Howard Hughes Medical Institute Investigator.What is surprising is that the newly found parrot brain structures had been known for 34 years but their link to speech was not made by scientists. The results also may lend insight into the neural mechanisms of human speech. The new interpretation was reported in the journal PLOS ONE on 24 June.By examining gene expression patterns, the new study found that parrot brains are structured differently than the brains of songbirds and hummingbirds, which also exhibit vocal learning. In addition to having defined centers in the brain that control vocal learning called 'cores,' parrots have what the scientists call 'shells,' or outer rings, which are also involved in vocal learning. The shells are relatively bigger in species of parrots that are well known for their ability to imitate human speech, the group found.This team included researchers from Denmark and the Netherlands who donated precious brain tissue for the study. They characterized the brains of eight parrot species besides the budgerigar, including conures, cockatiels, lovebirds, two species of Amazon parrots, a blue and gold macaw, a kea and an African Grey parrot.Even the most ancient of the parrot species they studied, the Kea of New Zealand, has a shell structure—albeit rudimentary. This suggests that the populations of neurons in the shells probably arose at least 29 million years ago.Before now, some scientists had assumed that the regions surrounding the cores had nothing to do with vocal learning."The first thing that surprised me when Mukta and I were looking at the new results is, 'Wow, how did I miss this all these years? How did everybody else miss this all these years?" said Jarvis, who is also member of the Duke Institute for Brain Sciences. "The surprise to me was more about human psychology and what we look for and how biased we are in what we look for. Once you see it, it's obvious. I have these brain sections from 15 years ago, and now I can see it."Most of the bird's vocal learning brain regions are tucked into areas that also control movement. These areas in parrots also show some special patterns of gene expression, which the scientists speculate might explain why some parrots are also able to learn to dance to music. This finding is a part of a much larger international effort to sequence the complete genomes of all 10,000 species of birds in the next five years, called the Bird 10K Project.