Mother tongue

Updating Magic Universe

It really is your mother tongue

Amid all the politically correct attempts to minimize the differences between the sexes, and ignore their contrasting roles in child rearing, how refreshing to see knock-down evidence pointing the other way! In results released today, researchers in Japan proclaim the special role of mothers in evolution’s most distinctive task for Homo sapiens – encouraging babies to chat.

The tale is quickly told because the RIKEN Brain Science Institute (located near Tokyo) has provided helpful diagrams. I’ve re-written the captions.

Special brain activity in mothers with babies at the babbling, pre-verbal stage appears in functional magnetic resonance imaging (fMRI) when they hear maternal baby-talk, technically known as infant-directed speech (IDS). The highest activity, denoted in red, is in the key language areas of the left hemisphere, Broca’s and Wernicke’s. Other women show a slightly raised response, but men don’t, whether they are fathers or not.

The fact that the special maternal brain activity switches on when it’s needed, and off again when it isn’t, reveals an astonishing evolutionary program.

The most amusing technical detail is that the investigators wanted to image the brains of mothers actually interacting with their babies, but they couldn’t. It was impossible for the mothers to keep their heads still. Listening passively to playbacks of baby-talk had to do instead. The experimental subjects were 35 first-time parents with pre-verbal infants, 30 men and women without any parenting experience, 16 mothers with toddlers who spoke two-word utterances and 18 mothers with children in elementary school.