title: Differentiating challenge reactivity from psychomotor activity in studies of children's psychophysiology: considerations for theory and measurement.
abstract: Current methods of assessing children's physiological "stress reactivity" may be confounded by psychomotor activity, biasing estimates of the relation between reactivity and health. We examined the joint and independent contributions of psychomotor activity and challenge reactivity during a protocol for 5- and 6-year-old children (N = 338). Measures of parasympathetic reactivity (respiratory sinus arrhythmia [RSA]) and sympathetic reactivity (preejection period [PEP]) were calculated for social, cognitive, sensory, and emotional challenge tasks. Reactivity was calculated relative to both resting and a paired comparison task that accounted for psychomotor activity effects during each challenge. Results indicated that comparison tasks themselves elicited RSA and PEP responses, and reactivity adjusted for psychomotor activity was incongruent with reactivity calculated using rest. Findings demonstrate the importance of accounting for confounding psychomotor activity effects on physiological reactivity.
authors.affiliation: Department of Psychiatry, University of California, San Francisco, CA 94118, USA. bushn@chc.ucsf.edu
authors.forename: Nicole R
authors.initials: NR
authors.lastname: Bush
authors.forename: Abbey
authors.initials: A
authors.lastname: Alkon
authors.forename: Jelena
authors.initials: J
authors.lastname: Obradović
authors.forename: Juliet
authors.initials: J
authors.lastname: Stamperdahl
authors.forename: W Thomas
authors.initials: WT
authors.lastname: Boyce
mesh_terms: D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D004644:Emotions / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D009043:Motor Activity / Q000502:physiology; D010275:Parasympathetic Nervous System / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011603:Psychophysiology; D012691:Serial Learning / Q000502:physiology; D012930:Social Dominance; D013060:Speech / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*; D013649:Taste / Q000502:physiology