Newborn brains sensitive to mom's voice: study

A mother's voice plays a unique role in activating the parts of their baby's brain involved in language learning, say Montreal researchers.

Electrical recordings made of infant brain activity within 24 hours of birth show the parts responsible for language processing react only to mom's voice, lead researcher Maryse Lassonde of the University of Montreal and Sainte-Justine University Hospital Research Centre said on Thursday.

The brain signals showed that while the infants did react to other women's voices, these sounds only activated the voice recognition parts of their brains.

"This is exciting research that proves for the first time that the newborn's brain responds strongly to the mother's voice and shows, scientifically speaking, that the mother's voice is special to babies," Lassonde said in a release. "[The] mother is the primary initiator of language."

The study marks the first brain research conducted on such young babies.

The research — published in this month's Cerebral Cortex journal — involved placing electrodes on the heads of 16 sleeping babies and then asking their mothers to make the short "A" vowel sound. The process was then repeated with a female nurse.

The scans showed their mothers' voices activated parts of the left hemisphere of the babies' brains, in particular those parts responsible for language learning. When the nurse spoke, it activated the right hemisphere of the babies' brains, which is associated with voice recognition.

The researchers say their study took into account the "novelty" aspect involved in processing a stranger's voice by arranging for the pregnant mother to meet with the nurse regularly before birth. In addition, speech analysis ensured the nurse's and mother's voices were comparable.

Scientists have long known that infants have some innate language capacities — when a baby hears the "A" sound, they will make the mouth shapes needed to imitate it, even if they have never seen it spoken.