Cardiac responsiveness to attention-demanding tasks in socially maladaptive children

Cardiac responsiveness to attention-demanding tasks in socially maladaptive childrenA psychofysiological study of the cardiac adaptivity to attention-demanding reaction time tasks demonstrated that children with a lesser variant of the pervasive developmental disorder (DSM-IV: PDDNOS) exhibit less cardiac responsiveness to attention tasks than healthy children do. We studied changes in heart rate variability (HRV), which were measured in a frequency band ranging from 0.07 to 0.14Hz. During the performance of an attention task, healthy children exhibited task load-related decreases in HRV. These decreases were found to be significantly smaller and not task load-related in a group of children with a PDDNOS who were judged to be not hyperactive. The decreases in HRV during task performance were almost absent in children with a PDDNOS who were moreover judged to be hyperactive. The magnitude of HRV decreases appeared to be significantly related to one of our task performance measures and to behaviour problems reported by the parents. Our results suggest a diminished vagal adaptivity to attention-demanding task situations in children with a PDDNOS, which is related to their resistance to unexpected changes in their daily routines.