Examining the stability of self-regulation across the first year

• In Event: 1-126 - Infants and Their Caregivers in Concert: Developmental Perspectives on Interpersonal Neurophysiology and Behavior

Integrative Statement

Across the first year, infants undergo significant development in their ability to self-regulate their affect and behavior. Longitudinal studies of infant self-regulation have primarily focused on the continuity of self-regulation behaviors at the group-level (e.g. Melinder et al., 2010; Lowe et al., 2012) without fully considering the stability of behaviors for particular infants (Mesman et al., 2013). The primary goal of this study is to examine both the continuity and stability of a key self-regulation behavior –distress—across the first year.
We examined behavioral and physiological self-regulation in 45 infant-mother dyads across two administrations of the Face-to-Face-Still Face Paradigm (FFSF; Tronick et al., 1978) when infants were 4 and 8 months old. We chose an age before and an age co-incident with important developmental milestones: progressing into the second half of the first year, infants show increased synchrony with caregivers while also learning to better redirect their attention and becoming more engaged in objects (Cohn & Tronick, 1987; Feldman, 2007).
We hypothesized that older infants’ would show higher distress overall because the violation of social contingencies in the FFSF would be more aversive for them, given their greater experience with the contingencies of social interaction. However, we also expected that the expression of distress would be moderated by individual differences in infant trait affect and physiological reactivity, as well as the degree of maternal vocal mimicry. To measure physiological regulation, infants’ and mothers’ respiratory sinus arrhythmia (RSA) for each phase were calculated from continuous ECG recordings. In infancy, decreases in RSA (i.e. vagal withdrawal) during a stressor are believed to reflect more effective regulation (Moore et al., 2009). Distress was operationalized as the proportion of time infants exhibited facial expressions of distress. Parents reported infant trait negative affect on the Infant Behavior Questionnaire-Revised (Gartstein & Rothbart, 2003).
Overall, 8-month-olds showed more distress compared to 4-month-olds, but there was no inter-individual stability across ages, r(43)= -0.08, p= 0.63. Multiple regression models revealed that 49% of the variance in distress during Reunion at 4 months was explained by concurrent Still-Face Distress, maternal vocal mimicry, and trait negative affect F(3,28)= 11.38, p= 0.003 (see Figure 1). In contrast, 42% of the variance of Reunion distress at 8 months was explained by concurrent Still-Face Distress, 4 month trait negative affect, and vagal withdrawal during the Still-Face at 4 months, F(3,28)= 6.88, p= 0.001 (see Figure 2). These results suggest that across both ages, trait negative affect and Still-Face Distress are key predictors of Reunion distress. However, for younger infants, distress was also predicted by maternal mimicry, whereas for older infants, distress was predicted by previous vagal withdrawal.
A follow-up Negative Affect X Phase interaction revealed that calm infants at 4 month olds showed the most Reunion distress at 8 months. Calm infants may receive a different type of parenting across the first year, leading to maternal unresponsiveness being more aversive over time. These results collectively highlight how infant temperament interacts with parenting to influence concurrent and future negative affect expression across the first year.

Authors

• Elizabeth B. daSilva, Indiana University-Purdue University Columbus
  Presenting Author

• Bennett I. Bertenthal, Indiana University
  Non-Presenting Author