The Development of Brain-heart Interplay during Child Affective Experience

The brain and heart interact dynamically to support affective experiences, yet how this affectrelated interplay develops throughout childhood remains poorly understood. In this study, we simultaneously recorded EEG and ECG from 148 children aged 5 to 10 years while they viewed movie clips selected to elicit fearful, happy, and neutral emotions. We applied a multi-method approaches to quantify brain-heart interplay: moment-to-moment EEG and ECG coupling, heartbeat-evoked potentials (HEP), and generative modeling of directional influences. We identified distinct age-related patterns. Children aged 5 – 6 years demonstrated stronger EEG-ECG correlations and heightened HEP amplitudes in response to fearful versus neutral movies, but these effects were diminished by 9 – 10 years. Directional modeling further revealed a developmental shift from a predominantly heart-to-brain to brain-to-heart influences with age. These findings collectively indicate that brain–heart interplay during affective experiences undergoes progressive calibration from reactive, sensation-driven mode toward more regulated, cortically integrated processing. Notably, while children’s self-reported affect following the movies became more homogeneous with age, their brain–heart interplay patterns became increasingly diverged, suggesting increasingly individualized neurophysiological pathways underlying the construction of shared affective states.