Dr. Pumpki Lei Su studies language development and caregiver-child interactions in autistic children. She describes parentese and her latest study in a YouTube video. Check out the video by clicking on the play button.
Parentese — the slower, simplified language with higher pitch, exaggerated intonation and elongated vowels that adults often use with infants — has been shown to facilitate language acquisition in neurotypical children, but it has not been clear whether the same holds true for the autistic population.
Dr. Pumpki Lei Su, assistant professor of speech, language, and hearing in the School of Behavioral and Brain Sciences and the Callier Center for Communication Disorders at The University of Texas at Dallas, studies language development and caregiver-child interactions in autistic children. In a new study published May 7 in the journal Infancy, she and her colleagues found that the social-interactive benefits of parentese in a child’s first year extends beyond the neurotypical population.
“Regardless of the differences a child might exhibit later in childhood, at least in the first year, autistic children are responding to parentese.”
Dr. Pumpki Lei Su, assistant professor of speech, language, and hearing
“Regardless of the differences a child might exhibit later in childhood, at least in the first year, autistic children are responding to parentese,” said Su, the study’s corresponding author, who is also affiliated with the Center for Children and Families. “Just like neurotypical infants, they were more likely to produce a speechlike vocalization — not laughing or crying — after an adult utterance in parentese register compared to adult register. The strength of that sequential association was the same regardless of whether the child went on to have an autism diagnosis.”
Su said researchers have been studying parentese for 50 years, which lead to robust evidence that infants prefer it and that it facilitates language in various ways. There are a variety of hypotheses, however, for why it helps infants learn to speak.
“Is it because the speech is happy and affectionate? Is it more engaging so that infants pay more attention? Some experts say when adults speak in an exaggerated manner, their vowel sounds also become more exaggerated, making the speech intrinsically easier to learn, but this also makes the speech more variable,” she said. “We think parentese may help language learning by encouraging the infants to respond and vocalize. We set out to investigate whether that is true and whether parentese would be as helpful for children who have differences in social mechanisms and are later diagnosed with autism.”
The study used data from the Marcus Autism Center, an affiliate of Children’s Healthcare of Atlanta. That data includes information gathered from the center’s cohort of infant siblings: children who have an older brother or sister already diagnosed with autism.
“Because having a family history of autism is a recognized risk factor, if one child in a family has already been diagnosed with autism, the likelihood of the next child also being diagnosed is about 20%,” Su said.
Language Interaction and Language Acquisition in Children Lab
Dr. Pumpki Lei Su directs the Language Interaction and Language Acquisition in Children Lab, where researchers study how various groups of children acquire language. Learn more about the researchers and their work on the lab’s website.
The researchers examined monthly daylong home recordings of 147 children in the first year of life at the time of the recordings. The group included both infant siblings who were later diagnosed with autism as well as those expected and confirmed to develop neurotypically. All participants were assessed again at 2 and 3 years of age to confirm their neurotype; 44 eventually were diagnosed with autism, and 103 were confirmed to be neurotypical.
Researchers coded about 30 minutes of caregiver-infant interaction per infant, examining caregiver-child vocal contingencies, using a metric to control for the overall amount of adult utterance and infant vocalization.
“We found that the likelihood of an infant speechlike vocalization following an adult utterance in parentese is significantly higher than the likelihood of an infant speechlike vocalization following an adult utterance in adult register,” she said. “We observed the same pattern in both groups. In other words, when adults speak in parentese, both autistic and neurotypical children are more likely to produce a speechlike vocalization immediately afterward.”
The findings support the notion that parentese might facilitate language learning by encouraging infants to respond and interact with their conversation partner. Su said that all parents have this tool at their disposal to help their children learn language.
“Previous studies in neurotypical children have shown that when you coach parents to use more parentese, it increases both the conversational turn-taking with the child and the child’s vocalization,” she said. “However, language input should be tailored to each child’s individual characteristics. That’s why we’re cautious about assuming that the same strategies effective for neurotypical children will work equally well for autistic children — and why it’s important to study this directly.”
Moving forward, Su and her colleagues will explore how parentese might facilitate vocabulary growth in autistic children ages 1½ to 4 years and whether the effect of parentese on word learning differs based on child characteristics.
“Individual variability could moderate the effect of parentese. We know some autistic children also experience sensory differences, such as hypersensitivity to sound. In those cases, the exaggerated intonation that characterizes parentese may feel overwhelming rather than engaging,” she said. “Parents are often the best judges of how their child respond. They understand their child the best and are constantly observing and adapting based on their child’s cues.”
For Su, who is also a speech-language pathologist, exploring how different styles of parental language input support language development is a subject close to her heart.
“I am a firm believer that if we can coach a parent to do something, they can integrate it into their daily life,” she said. “We can empower parents to become individualized clinicians for their own child.”
The senior study author is Dr. D. Kimbrough Oller of the University of Memphis. Other authors are affiliated with the Marcus Autism Center, Emory University School of Medicine, the University of Alabama and the University of Wisconsin-Madison.
This research was supported by grants from the National Institute on Deafness and Other Communication Disorders (R21DC021803, R01DC015108) and the National Institute of Mental Health (P50MH100029), which are components of the National Institutes of Health. Other supporters included the Plough Foundation, the Holly Lane Foundation, the Marcus Foundation, the Woodruff-Whitehead Foundation and the Georgia Research Alliance.