The Development of Dyadic Co-Regulation: The Role of Infant Vagal Tone and Temperament

• In Event: Poster Session 13
  In Poster Session: PS 13 Topic - Biological Processes: Psychophysiology

Abstract

A growing body of research demonstrates that sensitive caregiving is linked to infants emerging physiological and behavioral organization (e.g., Hastings et al., 2008; Meaney, 2010; Porter, 2003). In particular, it is thought that more sensitive caregiving may advantage children towards greater regulatory capacity while also diminishing stress reactivity (Calkins et al., 2008). Past findings highlight the potential dynamic interchange between caregiving systems and the organizational development of children’s physiology and behavioral characteristics (e.g., Propper & Moore, 2006). In this study, we extend previous work demonstrating concurrent linkages between mother-infant co-regulation and infants’ cardiac vagal tone, a measure of parasympathetic regulatory capacity. Using latent growth curve modeling, we examine relations between mother-infant co-regulation and infants’ physiological organization and temperament over three time points. Participants included 101 first-time mothers and their infants (50 females) at 6-, 9-, and 12-months of infant age. A 3-minute baseline ECG recording was collected at each time point. This was followed by a 20-minute unstructured free-play episode. Mother-infant interactions were coded during play using Fogel’s (1994) Co-Regulation Coding System. This system records moment-to-moment interactive dynamics (i.e., symmetrical, unilateral co-regulation). Mothers also completed the Infant Characteristics Questionnaire (ICQ; Bates, Freeland, Bennett, and Lounsbury, 1979). Latent growth curve models were adequately fit to the data and demonstrated that symmetrical co-regulation and vagal tone increased over time while unilateral co-regulation decreased in quadratic and logarithmic patterns. In contrast, fussiness and unpredictability decreased linearly over time. The significant variances of the intercepts indicated that the participants had different baselines, while the variances of the slopes indicated that participants changed at different rates. Intercorrelations among intercepts and slopes found that the intercept for symmetrical coregulation was positively linked to the intercept for infants’ vagal tone (.56, p < .01), demonstrating that higher vagal tone was linked to higher initial values in symmetrical interactions. Conversely, the intercept for unilateral co-regulation was negatively linked to vagal tone (-.51, p < .01) suggesting that higher level of unilateral co-regulation was linked to lower baseline levels of vagal tone in infants. Interestingly there was a negative correlation between the intercept for vagal tone and the slope for symmetrical (-.50, p < .01) and unilateral (-.40, p < .01) co-regulation suggesting that infants who started out with higher vagal tone had a slower rate of change in both patterns of co-regulation. Infant temperament was not associated with either the intercept or slope of either co-regulation pattern, but a link was found between the slopes of unpredictability and vagal tone suggesting that a faster rate of change in vagal tone was linked to a faster rate of change in unpredictability (.33, p < .05). An examination of potential covariates also showed that mother’s age was linked to symmetrical co-regulation in that older mothers had higher intercepts (.33 p < .05) and lower rate of change over time (-.27 p < .05). Consistent with Porges’ Polyvagal Theory (2011), findings suggest infants’ regulatory capacity plays a role in their ability to participate in sustained patterns of caregiver-infant interactions over time.

Author

• Chris L Porter, Brigham Young University
  Presenting Author