Babies born to blind mothers have better visual attention and memory than their counterparts with seeing parents, new research suggests.
The findings, published today (April 9) in the journal Proceedings of the Royal Society B, suggest that blind parents' inability to respond to gaze and eye contact doesn't harm their babies' development.
In fact, the need to rapidly switch between communicating with blind parents and the seeing world may actually enhance tots’ budding abilities by boosting their visual attention, the study found.
"The babies are very flexible, and they can easily adapt to the different modes of communication," said study co-author Atsushi Senju, a developmental cognitive neuroscientist at Birkbeck, University of London.
Past studies have shown that children with autism make less eye contact and follow people's gaze less often. Children in orphanages, who get little eye contact or social interaction, also show development problems.
Senju and his colleagues wondered how the lack of eye contact and gazing from blind parents affected their seeing children. Blind people may not be able to gaze into their little ones' eyes, but they still interact just as much through sound, touch and talking, Senju's team knew from past studies by other teams.
For the new study, researchers divided a sample of babies into two groups: five babies with a blind mother and a sighted or partially-sighted fatherand 51 babies with two seeing parents. The researchers then showed the two groups a video of people and compared the gaze of the babies of blind mothers to that of the babies with seeing parents. [11 Odd Facts About a Baby's Brain]
They evaluated the babies twice: once when the tots were between 6 months and 10 months old, and again when the kids were between 12 months and 15 months old. Then, they assessed the babies' brain development between ages 2 and 4.
Throughout the study, the babies of blind mothers were able to follow a person’s gaze and look at faces just as well as those whose mothers could see at comparable ages.
Moreover, in tests of their visual attention and memory, the babies of blind mothers actually performed better than their peers at all time points.
"We were totally puzzled to find it," Senju told LiveScience.
The team went back through the literature and found that bilingual babies also show a similar increase in visual attention. That led the team to wonder whether switching between sighted and blind caregivers could provide the same mental boost as switching between different spoken languages.
The findings show the remarkable plasticity of the baby's brain, said Andrew Meltzoff, a director of the University of Washington Institute for Learning & Brain Sciences, who was not involved in the study.
It also shows just how much babies are wired to seek out social interactions, especially with their mothers.
"One of the most striking and endearing findings in this paper is that the babies of blind mothers significantly increased their attention-getting vocalizations to the mother over and above that shown by babies of sighted parents," Metlzoff said. "They crave maternal social attention and switch modalities and produce auditory events that will get the mom’s attention. Brilliant!"