PHYSIOLOGICAL MARKERS IN EARLY INFANCY - STABILITY OF 1- TO 6-MONTH VAGAL TONE

Twenty-six full-term infants were evaluated at 1-, 3-, and 6-months po stpartum to explore the stability of Forges' (1985a) cardiac vagal ton e index. One-month vagal tone ((V) over cap) was not found to be assoc iated with either 3- or 6-month measures of cardiac vagal tone, howeve r, 3-month cardiac vagal tone was found to be predictive of 6-month ca rdiac vagal tone. Interestingly, 1-month heart period range was predic tive of 6-month heart period range. These findings both replicate and extend previous research examining early patterns of development in ca rdiac indices.