Vocal Tracts Of Monkeys Are Speech Ready, But Brain Does Not Allow Them To Talk
Known as the closest animal relative of humans, there is one thing monkeys cannot do -- talk. However, scientists recently found the vocal tracts of non-human primates like monkeys, apes and chimpanzees are actually speech-ready but their brains are not designed for it.
In a new study published in the journal Science Advances, humans can talk because of the brain's ability to control the vocal tract, not because of the presence of the tract itself. On the other hand, monkeys have their vocal tract but their brains are not wired to control it for speech.
A team of researchers at the University of Vienna found that monkeys and apes are unable to learn new vocalizations. Over the past decades, it is widely known that they cannot talk because of the limitations in their vocal anatomy, which includes the lips, tongue and larynx, the University of Vienna press release reports.
However, through the use of X-rays, the researchers looked inside monkeys' vocal tracts and found them to be more flexible than previously thought. During the scans, the monkeys were induced to vocalize, eat and make facial expressions. Though the monkeys can produce various sounds and could easily talk if they wanted to, the problem lies in their brains.
Brain Not Wired For Speech
"No one can say now that there's a vocal anatomy problem with monkey speech," Asif Ghazanfar at Princeton University and co-author of the study, said as reported by the New Scientist. "They have a speech-ready vocal anatomy, but not a speech-ready brain. Now we need to find out why the human but not the monkey brain can produce language," he added.
Meanwhile, other researchers in the field say the study is a great addition to the growing evidence that monkeys can create speech-like sounds. "I've pointed out for decades that monkeys could talk, with reduced intelligibility, if their brains could learn and execute the motor acts involved in speech," Philip Lieberman, at Brown University in Providence, Rhode Island, said.