Brain responses to surprising sounds are related to temperament and parent-child dyadic synchrony in young children.

This study investigated the relationship between temperament characteristics, parent-child dyadic synchrony and auditory event-related potentials (ERP) in 15 two-year-old children. Temperament was assessed with the Early Childhood Behavior Questionnaire, and parent-child dyadic synchrony was analyzed from video-taped play situations. Involuntary switching of attention toward surprising sounds was measured with auditory ERPs by quantifying the P3a response for repeated and nonrepeated novel, naturally varying sounds, presented in a continuous repetitive sound sequence. Lower negative emotionality, higher effortful control and higher dyadic synchrony were associated with larger P3a responses to repeated novel sounds. The results demonstrate that temperament is related to P3a responses in early childhood, and that parent-child synchrony associates with both temperament and P3a responses in a theoretically meaningful way.