Heart rate conditioning in newborn infants: Relationships among conditionability, heart rate variability, and sex

Abstract

Evaluated trace conditioning in 20 newborn infants by examining heart rate responses to the conditioned stimulus (CS), in anticipation of the unconditioned stimulus (UCS) and in the absence of the UCS. 2 sets of analyses were performed using subgroups based on preexperimental heart rate variability and sex. Preexperimental heart rate variability was related only to the response to the CS, with only the high-variance Ss showing a conditioned deceleration and exhibiting a change in response across trial blocks. Only the females exhibited conditioned decelerations in response to the CS and in anticipation of the UCS. In the absence of the UCS, only the experimental group as a whole responded with a deceleration. The relationship between sex and heart rate variability was also examined. Data suggest that females tend to have higher levels of heart rate variability which parallels their greater conditionability. (27 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)