February 27, 2013
Brains Of Premature Babies Are Capable Of Recognizing Syllables
redOrbit Staff & Wire Reports - Your Universe Online
Infants who are born up to three months premature are capable of recognizing different syllables in human speech patterns, according to new research published in the latest edition of the journal Proceedings of the National Academy of Sciences (PNAS).According to Mark Prigg of the Daily Mail, the study discovered that the human brain is capable of discerning between different spoken sounds earlier than scientists had previously believed.
Furthermore, the researchers discovered that the way the brain of a newborn processes language is similar to how the adult brain processes the same information, Prigg said. Among those changes were “specific neurological reactions to changes from the 'ba' to 'ga' sound and to a male to female voices,” he added.
The researchers, including Dr. Fabrice Wallois of Picardie University in France, told BBC News Online Health Editor Michelle Roberts that they believed that it was unlikely that those infants´ experiences outside their mothers´ wombs would have had any impact on their findings. Furthermore, they believe that their findings provide evidence that babies are able to develop linguistic skills while still at the fetal stage of development.
“Experts already know that babies are able to hear noises in the womb - the ear and the auditory part of the brain that allow this are formed by around 23 weeks' gestation. But it is still debated whether humans are born with an innate ability to process speech or whether this is something acquired through learning after birth,” Roberts said. “The authors of the study in PNAS say environmental factors are undoubtedly important, but based on their findings they believe linguistic processes are innate.”
“Our results demonstrate that the human brain, at the very onset of the establishment of a cortical circuit for auditory perception, already discriminates subtle differences in speech syllables,” Dr. Wallois and his colleagues said in their study, according to BBC News. However, they also add that their research “does not challenge the fact that experience is also crucial for their fine tuning and for learning the specific properties of the native language.”
During their research, Dr. Wallois and his associates studied a dozen sleeping premature infants, all of whom were born after 28 and 32 weeks of development. They used “powerful non-invasive scanners” to analyze the babies while playing voice recordings, Prigg explained.
“This is the earliest age for neuronal responses to external stimuli and Prof Wallois found the premature brain can perceive differences in syllables,” the Daily Mail reporter said. “In addition although the tests produced responses in the right frontal region of the brain — the first part of the brain to form — syllabic changes also sparked responses in the left hemisphere“¦ This suggests certain linguistic brain areas exhibit a sophisticated degree of organization as early as three months prior to full term.”
Dr. Wallois told Prigg that his team noticed several areas of similarity between the linguistic network of the infants and those of adults. Syllables resulted in larger responses to the right side of the brain than the left in most areas of the brain, he said. However, this was not true in the posterior temporal region, where the left side showed responses that were quicker and longer-lasting than those found in the right hemisphere.
“Second, discrimination responses to a change of phoneme” — or a set of distinct speech-related sounds — “and a change of human voice (male vs. female) were already present and involved inferior frontal areas, even in the youngest infants,” he told the Daily Mail. “Third, whereas both types of changes elicited responses in the right frontal region, the left frontal region only reacted to a change of phoneme.”
“These results demonstrate a sophisticated organization of areas at the very onset of cortical circuitry — three months before term. They emphasize the influence of innate factors on regions involved in linguistic processing and social communication in humans,” Dr. Wallois added.