TOKYO, 10 September 2003 — Babies can differentiate a language from noise at birth, suggesting either they learn it while in the womb, or humans have innate language skills, according to a research report set for publication yesterday.
The joint study by Italian, Japanese and French laboratories covered 12 Italian newborn babies aged two to five days and used speech samples from two Italian mothers whose infants did not participate in the experiment, according to a press preview copy of the research paper.
The study was set to be published online on the Proceedings of the US National Academy of Sciences later yesterday.
The study used an optical topography device newly developed by Hitachi Ltd. to detect change in cerebral blood volume and oxygen saturation.
The system uses near infrared rays and displays blood hemoglobin levels in the brain in different colors.
When exposed to normal, forward speech, the newborns showed a significantly greater activity in the left hemisphere (LH) of their brains than in the right hemisphere, according to the research.
The LH is known to have connections with language processing.
In contrast, no significant differences by hemisphere were observed during the playing of tapes of backward speech or silent conditions.
The study “provides the demonstration that the neonate (newborn) brain responds specifically to normal speech only after a few hours of experience with speech signals outside the womb,” the researchers said in a joint paper.
The paper said the study “provides clear evidence that, at birth, the human brains is functionally organized to process speech in the LH, but not matched reversed utterances.”
A similar asymmetry by hemisphere is seen in adult brains, it said.
This “implies that humans are born with a brain organization geared to detect speech signals and pay attention to utterances produced by their surroundings,” it said.
The laboratories which took part in the study are the International School for Advanced Studies of Italy, the Hitachi Advanced Research Laboratory of Japan and France’s National Center for Scientific Research and School of Advanced Studies in Social Sciences.