ATLANTA (December 14, 2022) – Researchers have found when caregivers sing to infants, babies instinctively synchronize their gaze with the beat of the music by looking into their caregiver’s eyes. The new research was recently completed by Marcus Autism Center, a subsidiary of Children's Healthcare of Atlanta, Vanderbilt University Medical Center and Emory University School of Medicine and published in the Proceedings of the National Academy of Sciences of the USA. Results show that synchronization supports infant social learning and may also have implications for children with autism spectrum disorder.
“This study shows that synchronization shapes the social experience of infants, changing what they look at and what they see,” says Warren Jones, PhD, study co-principal investigator, Director of Research at Marcus Autism Center, and Nien Distinguished Chair in Autism at Emory University School of Medicine. “Infants and caregivers interact in an intricate dance. This reveals the very basic steps of that dance and how those steps subtly but importantly change infant and caregiver behavior on a moment-by-moment basis.”
Dr. Jones, in collaboration with Miriam Lense, PhD, study co-principal investigator and Assistant Professor at Vanderbilt University Medical Center, wanted to understand the most basic elements of social interaction, part of a larger effort to study how social interaction and synchronization may be disrupted in children with autism. Synchronization is observed in other physical and biological systems, such as synchronized sleep-wake cycles and the synchronization of heartrate and breathing.
Now, the researchers wanted to determine if the behavior of infants as young as two months of age, when babies first begin to engage in reciprocal social interaction, synchronizes with the behavior of their caregivers. To study this, the team made use of a form of infant-caregiver interaction found in all human cultures: singing to infants.
“Experimentally, infant-directed singing takes a lot of different social cues and makes those cues rhythmic, repeatable and predictable,” says Dr. Jones. “This is helpful because it gives us a tool to understand the way in which rhythmic behavior of a caregiver might synchronize the behavior of an infant.”
The researchers tested infants when they were two and six months old. During testing, the researchers used eye-tracking technology to measure the movements of infant’s eyes while they watched videos of caregivers singing.
Results showed that infants synchronized their gaze to caregivers’ eyes in time to the rhythm of singing. They were more likely to look at a caregiver’s eyes on the beat than between beats. In addition, singing caregivers synchronized their facial expressions toward infants: on each beat, the singing caregivers spontaneously presented more wide-eyed and positive facial expressions, fewer neutral facial expressions, and were less likely to blink. Without conscious awareness, the simple act of singing changed caregiver behavior to be more positive and engaging on each beat, and that change in behavior was synchronized with changes in how infants looked at their caregivers.
When the researchers manipulated the timing of the beats, subtly changing the rhythm by altering the videos, so that the timing of each beat became less regular and less predictable, infants’ behavior also changed. They were less likely to increase their gaze toward the caregiver’s eyes.
“This study is important because it reveals a remarkable physical coupling between caregiver behavior and infant experience,” says Dr. Jones. “It shows us a very basic building block of social interaction, how early it emerges, and also suggests a potential vulnerability in autism, if synchronization in children with autism is reduced or disrupted.”
The study is part of a larger effort to investigate how synchronization may be disrupted in children with autism, with the goal of using music to support early intervention for improving social communication. Future work will test these effects in a randomized controlled trial to enhance behavioral intervention for kids with autism using music. The goal of that research is to test whether empirically validated behavioral treatment approaches in autism can be enhanced through the use of music.
“Studies like this one help us to understand how music affects experience at a very basic level, and how music may be leveraged to support better health and healthy social development,” says Lisa Gilotty, PhD, chief of the Research Program on Autism Spectrum Disorders at the National Institute of Mental Health, one of the agencies that supported the study.
The study was funded by the Sound Health Initiative, a partnership between the National Institutes of Health and the John F. Kennedy Center for the Performing Arts to foster research into the potential for music to promote health and well-being (grant MH123029). Additional support was given by the GRAMMY Foundation, the National Institute of Mental Health (grant MH100029), and the National Institute on Deafness and Other Communication Disorders (grant DC016710).
About Children's Healthcare of Atlanta
As the only freestanding pediatric healthcare system in Georgia, Children’s Healthcare of Atlanta is the trusted leader in caring for kids. The not-for-profit organization’s mission is to make kids better today and healthier tomorrow through more than 60 pediatric specialties and programs, top healthcare professionals, and leading research and technology. Children’s is one of the largest pediatric clinical care providers in the country, managing more than one million patient visits annually at three hospitals, Marcus Autism Center, the Center for Advanced Pediatrics, urgent care centers and neighborhood locations. Consistently ranked among the top children’s hospitals by U.S. News & World Report, Children’s Healthcare of Atlanta has impacted the lives of kids in Georgia, across the United States and around the world for more than 100 years thanks to generous support from the community.
About Marcus Autism Center
Marcus Autism Center is a not-for-profit organization and a subsidiary of Children’s Healthcare of Atlanta that treats more than 5,000 children with autism and related disorders a year. As one of the largest autism centers in the U.S., Marcus Autism Center offers families access to the latest research, comprehensive evaluations and intensive behavior treatments. With the help of research grants, community support and government funding, Marcus Autism Center aims to maximize the potential of children with autism today and transform the very nature of autism for future generations.
About Emory University School of Medicine
Emory University School of Medicine is a leading institution with the highest standards in education, biomedical research and patient care, with a commitment to recruiting and developing a diverse group of students and innovative leaders. Emory School of Medicine has more than 2,800 full- and part-time faculty, 556 medical students, 530 allied health students, 1,311 residents and fellows in 106 accredited programs, and 93 MD/PhD students in one of 48 NIH-sponsored Medical Scientist Training Programs. Medical school faculty received $456.3 million in external research funding in fiscal year 2018. The school is best known for its research and treatment in infectious disease, neurosciences, heart disease, cancer, transplantation, orthopaedics, pediatrics, renal disease, ophthalmology and geriatrics.