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Learning bonus for blind parents' kids

Fast communicators Infants of blind parents learn to communicate in different ways with their parents and other sighted adults - a skill that enhances their development, a new study shows.

The findings add an unexpected twist to our understanding of how early life experiences affect the development of a baby's highly changeable brain, say researchers.

Normally, babies start learning vital social skills within days of birth by watching other people, noticing their faces and eyes, and reading important social signals such as eye contact, explains study co-author developmental psychologist Kristelle Hudry from La Trobe University in Melbourne.

Babies who miss out on those normal interactions - for example those born blind or those who are severely neglected - can experience difficulties with language and communication later on.

In the latest study, Hudry and colleagues in the UK and Canada set out to explore in another way how these skills develop, by studying five infants who could see, but whose primary caregiver was blind.

Their findings appear in the journal Proceedings of the Royal Society B.

"These children are being raised in very warm, loving families, the only difference is that the parent can't see, so the parent isn't able to respond to the child's face in the usual way, and perhaps isn't using things like pointing and eye contact to interact with the child," Hudry says.

The researchers followed the infants from the ages of six months to nearly four years, studying how they interacted with their blind parent and other adults. They also measured the children's general thinking, language and physical development.

By the time the researchers first started working with the infants, at around six months of age, subtle differences had already become apparent in the way they were interacting with their blind mothers and sighted adults who were doing the testing, says Hudry.

Fast and flexible

The study children began using their voices to communicate with their parents more quickly than average, while with other sighted adults they used the usual visual communication techniques like eye-contact and pointing just as effectively as children with sighted parents.

"That's showing that the lack of the mum's eye gaze or visual skills isn't putting these babies at a disadvantage, it's actually perhaps helping them become kids who are a bit more flexible, able to change their social behaviour a bit better depending on the situation," says Hudry.

"That's a really nice finding for families who might be in this situation. Just because the parent can't use their eyesight in the usual way, the child isn't at a disadvantage."

In fact, when they tested the infants' more general learning faculties, such as memory and attention, the researchers were surprised to find that the children of blind parents often scored better than a group of children of sighted parents.

Exactly why this should be the case isn't clear, they say.

"This is a somewhat unexpected finding," says Atsushi Senju from the University of London, the study's first author.

"One possibility is that the need to constantly switch between different modes of communication for sighted and blind adults might have facilitated their cognitive development."

The benefit observed for the children of blind parents might be similar to the cognitive boost experienced by bilingual infants who have to constantly switch between two different languages, he notes.

Indeed, the study shows that infants can develop non-verbal communication skills as flexibly as they develop language skills.

"Infants can proactively learn how to communicate effectively for different individuals, and switch [strategies] flexibly between different adults," Senju says.

"It gives us an insight [into] how children can easily learn new cultures and new technologies so easily. Such a capacity might be fundamental to the way humans adapt to the complex social and cultural environment."