Why babies can learn two languages as efficiently as one
Researchers at the AAAS Annual Meeting in Boston presented two separate but equally fascinating sets of findings about human language development on Thursday.
Janet Werker, a psychologist at the University of British Columbia, presented findings that showed 7-month old infants can distinguish between two totally different grammatical structures. The research helps us understand why babies can learn two languages as efficiently as one.
And Erich Jarvis, an associate professor of neurobiology at Duke University, said that his experiments showed humans and songbirds share similarities in the brain -- traits that birds who don't learn their sounds do not share.
Werker's findings were published today in Nature Communications. Her study tested bilingual infants growing up with two very different languages - English, which puts prepositions and articles before objects (I'm going to the AAAS meeting), and a language like Japanese or Farsi, which does the opposite (AAAS meeting to, house the).
The question: what cues do babies use to distinguish such radically different grammatical structures?
Werker found that babies can use both pitch cues (the pitch of important words) and duration cues (the length of important words) to distinguish between the two languages. For example, in English, regular words like "the" often come before longer, important words (house, dog, daddy). But in Japanese, the pitch of those important words is often higher.
Babies can distinguish the difference as young as seven months.
Jarvis' work, which is not yet published, suggests that birds who can reproduce sounds (songbirds like zebra finches and budgies) share brain similarities with humans.
Most animals respond to sound -- dogs can learn their names and to perform an action when they hear the word "sit," for example. But reproducing those sounds is unique: dogs can't say "sit."
Jarvis found that humans and songbirds who learn and reproduce their sounds both produce specific molecules in the communication regions of the brain. But doves and quails that don't learn sounds don't produce these molecules.
Researchers believe that singing was a precursor for spoken language.
Kate Allen is the Star's global science and technology reporter. She is reporting from the AAAS meeting in Boston this week. Follow her on Twitter @katecallen