Baby Talk

Asian newborn baby sitting on mother knees. She is looking at her mom and smile. Mother holding baby hands. Seen from top side view through mother hair and focus on baby face.

Researchers explore early signs of autism in children.

Baby talk—that short, sing-song, sometimes silly, melodic approach to speech—is a universal practice among parents. And infants prefer it. A horse becomes horsie; a dog becomes doggie; and mom and dad become mama and dada. Repetition and exaggerated intonation are key components of “motherese,” or infant-directed speech. But when a little one doesn’t respond to baby talk, it can be an early sign of autism spectrum disorder (ASD).

Researchers at UC San Diego School of Medicine used numerous techniques to pinpoint the regions of the brain responsible for a child’s response to baby talk.

“This new study, which combined state-of-the-art brain imaging, eye-tracking and clinical testing, opens the door toward precision medicine in autism,” says senior author Eric Courchesne, PhD ’75, professor of neurosciences at UC San Diego School of Medicine.

Courchesne says the approach generates new insights into how the brain is developing in children with autism.

“For the first time, we are seeing what the possible brain impact is for children with autism who fail to pay attention to social information,” he says.

The investigators suspected that little ones with ASD experience impaired development of innate mechanisms that respond to baby talk. To test this, they conducted a series of tests involving 71 toddlers and 14 adults. They used functional magnetic resonance imaging (fMRI) to measure sleeping toddlers’ brain activity in response to baby talk and other speech. The researchers also assessed the youngsters’ social and language development and used eye-tracking technology to measure their responses to women speaking baby talk, as well as non-speech computer sounds and images.

The study found different responses among typically developing children and those with ASD. Those children with the poorest neural responses to baby talk displayed the most severe social symptoms, poorest language outcomes and most impaired behavioral preference and attention toward baby talk. By comparison, infants and toddlers with typical development showed the strongest responses and affinity to baby talk.

The researchers confirmed their findings by correlating eye-gaze patterns to brain and behavioral responses, noting that the superior temporal cortex, a brain area that processes sounds and language, responded more weakly to baby talk and emotion speech in children with ASD. The opposite was true among typically developing children, who displayed a strong superior temporal neural response. A small number of toddlers with ASD showed strong brain activation and interest in baby talk, as determined by eye-tracking.

“The fact that a few children with autism did show strong brain activation and good attention to motherese speech is encouraging,” says study co-author Karen Pierce, MA ’93, PhD ’96, professor of neurosciences at UC San Diego School of Medicine and co-director of the Autism Center of Excellence with Courchesne. “First, because it suggests that these particular toddlers with autism are likely to have good outcomes, a newly discovered and important subgroup. And second, it suggests a novel avenue for treatment.”

Learn more about the Autism Center of Excellence.