Babies babble with fingers

2001-09-06 13:26

Paris - Babies born to deaf parents "babble" with their fingers, learning the rhythm of sign language, psychologists say.

Three babies born to deaf parents, and who had only been exposed to sign language since birth, were compared with three babies who had been exposed to speech.

All of the infants had normal hearing.

The six wore tiny light-emitting diodes on their hands which enabled a computer system to track their movements as they played or were presented with objects.

The babies with deaf parents had remarkably different hand movements from their counterparts, according to the study led by Laura Ann Petitto of Dartmouth College in the US state of New Hampshire.

The sign-exposed tots all carried out low-frequency hand movements in the "sign space" in front of their bodies û the window which is used for expression in signed languages. Both groups of children also had high-frequency hand activity outside the sign space.

"Quantitatively, the low-frequency hand activity corresponds to the rhythmic patterning of adult sign-syllables," the authors report in Thursday's issue of Nature, the British science weekly.

This "silent linguistic babbling" supports the theory that babbling - whether vocally or with the fingers - is essential for learning the rhythmic patterns that bind syllables, they contend.

That notion is opposed in some quarters.

Some biologists suggest that babbling, which develops from around seven months, is a meaningless motor activity caused by the opening and closing of the baby's mouth and jaw. -AFP

- SAPA