Japanese researchers say that mothers’ baby talk plays a crucial role in the early stages of infant language acquisition.

To study the underlying brain mechanisms of baby talk, researchers at the Riken Brain Science Institute in Tokyo used functional magnetic resonance imaging (MRI) in 35 first-time parents whose infants hadn't started to speak.

Then they compared the data to 30 men and women without any parenting experience. The researchers also studied 16 mothers with infants who spoke two-word utterances and 18 mothers with children in elementary school.

They monitored the brain activity while the mothers listened to recorded baby talk, which triggers brain activation patterns similar to those that occur when someone imitates baby talk, also called infant-directed speech (IDS).

Analysis of brain scan data found the mothers with preverbal infants had increased brain activity in areas of the brain that govern language. Increased brain activity did not occur in any other group, including mothers whose children had started to speak, according to a Riken news release.

The investigators also found those who were extroverts also had increased cortical activation in speech-related motor areas of the brain among mothers with preverbal infants.

They found clear distinctions in how people process and generate IDS. This is evidence that baby talk acts as a link for linguistic transfer from mother to infant and plays a crucial role in the early stages of infant language acquisition, according to the study authored by Reiko Mazuka, Yoshi-Taka Matsuda and colleagues.

The findings were released in an upcoming print issue of the journal NeuroImage.