The first sweet sounds of a newborn, those little whispers of joy that fill parents with wonder, hide a deep and surprising connection between the heart and language development. A recent study conducted by Jeremy I. Borjon, an associate professor of psychology at the University of Houston, revealed that infants' initial vocal attempts are closely linked to fluctuations in their heartbeat. The study, published in the Proceedings of the National Academy of Sciences, could open new perspectives on understanding linguistic development and early signs of communication disorders.
For infants, producing recognizable sounds is not just a cognitive issue but a motor skill that requires coordination of many muscles. What was previously unknown is that this complex process is tightly connected to variations in heart rhythm. The research involved 34 infants aged 18 to 27 months, analyzing 2,708 vocalizations made while playing with an adult. Although most sounds were not yet identifiable as complete words, a surprising pattern emerged: changes in heartbeat were synchronized with the murmurs and utterances that the infants continued to produce.
As noted by the authors of the research, fluctuations in heart rhythm are natural in all mammals and follow a rhythmic pattern, increasing and decreasing regularly. According to the findings presented by Professor Borjon, infants tend to 'adjust' to this rhythm, vocalizing more when the heartbeat reaches a maximum peak or a minimum point. The sounds produced during these peaks are longer, while those emitted before declines are more easily recognized as words by untrained listeners.
'Every sound produced by an infant helps their brain and body learn to coordinate, a fundamental step towards language development,' Borjon explained. These results emphasize how the autonomic nervous system—the one that regulates vital functions such as heartbeat and breathing—plays a crucial role in the early years of a child's life.
The link between recognizable vocalizations and slowing of the heartbeat also suggests that a predictable development of the autonomic nervous system is essential for language formation. Experts have highlighted the importance of further studying this relationship to better understand how language emerges and to identify potential risk factors related to atypical development.