Adrenocortical Interdependence in Father-Infant and Mother-Infant Dyads: Attunement or Something More?

• In Event: Poster Session 02
  In Poster Session: PS 02 Topic - Biological Processes: Psychophysiology

Abstract

Dysregulation of the hypothalamus-pituitary-adrenal-axis (HPA-axis) early in life has implications for future psychopathology. Parents may play a role in helping infants regulate their HPA-axis response to stress by how they respond to their infants, leading to physiological synchrony. This synchrony between parents and their infants has mostly been studied among mother-infant dyads. The goal of this study was to advance research on cortisol attunement by including cortisol assessments for mother-infant and father-infant dyads during a stressful lab-based procedure and utilize the dyadic Actor-Partner-Interdependence Model (APIM) to model adrenocortical interdependence between parents and infants, and both actor effects (cross-time stability) and partner effects (cross-lagged paths from infant to parent, and vice versa).
Participants were 180 families with 12-month-old infants. Mother-infant and father-infant dyads participated in a Strange Situation Procedure (SSP; counterbalanced laboratory visits). Saliva was collected prior to the SSP (T1), 20-minutes after the first parent-infant separation of the SSP (T2), and 40-minutes after the first parent-infant separation (T3). The SSP was followed by a 15-minute teaching task. Infant distress during parent-infant separations in the SSP, and infant negativity and parental sensitivity during the teaching task were included in a series of exploratory post-hoc APIM models as potential mediators of parent and infant cortisol responses.
Preliminary analyses showed different mean change in cortisol for parents and infants. Whereas parents cortisol was high at T1 and decreased over time, infants’ cortisol slightly declined over time among mother-infant dyads and increased following separation among father-infant dyads with a subsequent decrease to baseline levels. APIM analyses indicated significant stability effects of cortisol for both infants and parents, and significant infant T2 cortisol to parent T3 cortisol (partner-effect) in both mother-infant and father-infant models. Within-time interdependence (residual variance correlations) between parent and infant cortisol at T2 and T3 was not significant, providing little support for within-time attunement. Post-hoc analyses explored mediators of the significant infant T2 to parent T3 cross-lagged path for both parent-infant dyads. There was support for an affective-spillover model in which infant distress in the SSP predicted infant cortisol at T2, which then significantly predicted infant negativity during mother-infant interaction following the SSP, but there were no further relations predicting either infant or parent cortisol at T3, suggesting only partial mediation (Figure 1). Parent-infant cortisol does not appear to be interdependent in the current lab-based study using the SSP to suggest there is adrenocortical attunement for either mother-infant or father-infant dyads. There is some evidence that infant distress to separation during the SPP predicts infant’s cortisol production after the SSP that then predicts further negativity during subsequent mother-infant interactions that future research should examine further as the mediating link between parent and infant cortisol attunement. Findings differed slightly for father-infant dyads (Figure 1), with infant cortisol post-SSP predicting less infant negativity during interactions with more sensitive fathers. Research is needed to understand whether there is evidence of adrenocortical attunement across parents and infants in different settings and exactly what the mediating biobehavioral mechanisms are that link the HPA-axes of parents and infants.

Authors

• Lauren R. Bader, Institute for Advanced Study in Toulouse
  Presenting Author

• Lin Tan, University of Michigan - Ann Arbor
  Non-Presenting Author

• Richard Gonzalez, University of Michigan - Ann Arbor
  Non-Presenting Author

• Ekjyot Kaur Saini, Pennsylvania State University, University Park
  Non-Presenting Author

• Yeonjee Bae, University of Michigan - Ann Arbor
  Non-Presenting Author

• Livio Provenzi, La Nostra Famiglia Associazione
  Non-Presenting Author

• Brenda L Volling, University of Michigan - Ann Arbor
  Non-Presenting Author