Travel to the misty cloud forests of Costa Rica, and you might find yourself being serenaded by some of the most tuneful vocal virtuosos in the animal kingdom: Alston's singing mice.
Don't judge them by their size; these tiny divas can belt out ballads like no other. In fact, they're known for their singing duels, where they challenge competitors to a song-off in a melodic battle over territory or mates. Their songs are so complex, and require such dextrous vocal reflexes, that researchers are now looking at these mice as the best mammalian analogue to human speech, reports MedicalXpress.com.
In fact, in studying these mice, scientists have identified a peculiar brain circuit that might also be responsible for how humans manage back-and-forth conversation at such high speeds. The finding could sprout a whole new field of research that looks at how modules in the brain are capable of managing precise, sub-second vocal turn-taking. And it could lead to new breakthroughs in treating conditions that affect speech, such as stroke.
"Our work directly demonstrates that a brain region called the motor cortex is needed for both these mice and for humans to vocally interact," said senior study author Michael Long. "We need to understand how our brains generate verbal replies instantly using nearly a hundred muscles if we are to design new treatments for the many Americans for whom this process has failed, often because of diseases such as autism or traumatic events, like stroke."
The real magic to the songs of these mice, and to human conversation, is the coordination between brain processing and the musculature of sound production. To produce vocalizations between singing duelists that bend and break so rapidly, and respond so immediately to a singing partner, muscle contractions must be expertly controlled and with breakneck speed.
Using electromyography, an imaging technique that can captures electrical signals as the brain generates muscle contractions, researchers were able to pinpoint a region within the motor cortex, known as the orofacial motor cortex, or OMC, that appears to be the hotspot that regulates both song timing in singing mice and, perhaps, rapid conversation in people.
The next step will be to apply the models that have been generated by studying singing mice, to humans. If they map onto one another, it could lead to a deeper understanding of the neural evolution of advanced vocal communication, as well as enlighten us about how two brains are able to engage in conversation.
It's an unexpected brethren, between us and these Cyranos of the rodent world. Think of them the next time you're watching humans duel it out on televised talent shows like "The Voice" or "American Idol." We're not so far removed from the natural world as we sometimes like to think.
And if you've never heard a singing mouse, you can hear it in the video above.