Experience, gender and personality appear to influence the "baby talk" parents use when interacting with their infants, say Japanese researchers.
Baby talk is found across languages and cultures, but the brain mechanisms that underlie it are not known.
Reiko Mazuka, Yoshi-Taka Matsuda and colleagues at the Riken Brain Science Institute in Tokyo used functional MRI to assess brain activity in 35 first-time parents whose infants hadn't started to speak (preverbal) and compared them to 30 men and women without any parenting experience.
The study also included 16 mothers with toddlers who spoke two-word utterances and 18 mothers with children in elementary school.
The participants' brain activity was monitored while they listened to recorded baby talk, which triggers brain activation patterns similar to those that occur when someone speaks baby talk, also called infant-directed speech (IDS).
The brain scans showed that mothers with preverbal infants had increased brain activity in areas of the brain that govern language. This heightened brain activity did not occur in any other group, including mothers whose children had started to speak, according to a Riken news release.
Among mothers with preverbal infants, those who were extroverts also had increased cortical activation in speech-related motor areas of the brain, the investigators found.
The results show that there are 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, the researchers concluded.
The findings were released online in advance of publication in an upcoming print issue of the journal NeuroImage. (August 2010)