• respiratory sinus arrhythmia;
  • children;
  • vagal control;
  • sleep problems


We examined the role of children's emotional intensity and vagal functioning in predicting sleep problems in healthy elementary school-aged children. Children's dispositional emotionality was examined via parent report, and their vagal regulation was assessed via respiratory sinus arrhythmia (RSA) during a baseline and a reaction time (RT) task. Sleep problems were examined through both child reports, and home monitoring with wrist actigraphs for four consecutive nights. Increased emotional intensity was predictive of a reduced amount of sleep and increased night activity. Less apt vagal regulation, characterized by lower levels of RSA suppression to the RT task, was predictive of increased sleep problems as assessed through both subjective and actigraphy-based measures of sleep. Results indicate that children's emotionality and regulation predict unique variance in the amount and quality of children's sleep, and suggest that they may underlie, at least in part, sleep disturbances in healthy children. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46:307–317, 2005.