Respiratory sinus arrythmia: A potential measure of attention responses in newborns

Abstract

In recent years, developmental psychologists have sought to develop practical measures for assessing newborn response capabilities. In this regard, researchers have questioned whether measurements of heart rate variability associated with respiratory activity, i.e., respiratory sinus arrythmia (RSA), may serve as an index of newborn attentional responsivity to auditory stimulation. A preliminary study provided promising evidence that newborns exhibit both immediate and sustained increases in RSA during presentations of their mother's voice.;Experiment 1 was aimed at both replicating the findings of the preliminary study, and comparing the newborn's RSA response to its mother's voice and its performance on a standard behavioral test of newborn orientation capabilities. First, subjects were presented three one-minute alternations of a period of silence, followed by a period of its mother's voice. Second, subjects were tested on the behavioral orientation test. Newborns exhibited no immediate or sustained increases in RSA during mother's voice periods, but rather an immediate decrease in RSA. Furthermore, there was no relationship between the behavioral and physiological responses.;Experiment 2 was similarly designed both to examine the newborn's response to rattle sounds, and to compare the newborn's behavioral and physiological responses. Newborns exhibited no sustained changes in RSA in response to the stimulus, but showed an immediate increase in RSA during rattle sound periods. Moreover, a pronounced relationship existed between the behavioral and physiological measures.;Experiment 3 was conducted to investigate whether RSA can serve as a measure of auditory discrimination between mother's voice and rattle sounds, as well as to determine whether a relationship exists between the newborn's physiological and behavioral responses. The procedure was similar to that in Experiment 1. Newborns exhibited no differential RSA responses to the two stimuli. As a result, a comparison could not be made between the behavioral and physiological responses.;Several interpretations are offered to explain why newborns did not exhibit either increases in RSA to mother's voice or a differential response to mother's voice as compared to rattle sounds. However, the findings in Experiment 2 provide support for the proposal that RSA may serve as an index of newborn attentional responsivity to auditory stimulation.