Poster #22 - Respiratory sinus arrhythmia and cortisol reactivity in toddlers predict observed fear and maternal-reported behavior problems

• In Event: 1-169 - Poster Session 04
  In Poster Session: PS 04 Section - Biological Processes: Psychophysiology

Integrative Statement

Parasympathetic nervous systems (PNS) and hypothalamic–pituitary–adrenal (HPA) axis are key components of the stress response system. Individual differences in PNS and HPA activity have been linked with children adjustment. RSA suppression is often associated with less emotion dysregulation and fewer behavior problems (Calkins & Dedmon, 2000); whereas cortisol reactivity predicts internalizing problems (Granger et al., 1994). Physiological stress response was also related to children’s observed behaviors. RSA augmentation is associated with dysregulated fear (Buss et al., 2018); elevations in cortisol have been related to fearfulness (Buss et al. 2004) and behavioral inhibition in children with insecure attachment (Nachmias et al., 1996). However, the findings in this area are equivocal. Taking a multisystem approach may provide insight. The current study aimed to examine the joint influence of PNS and HPA on child behavior problems (i.e., internalizing and externalizing behaviors) concurrently and longitudinally. Dysregulated fearful behavior, a precursor of social withdrawal and social anxiety disorders (Buss et al., 2013), was also included as an indicator of child maladjustment.

Data from 62 children (33 girls) were drawn from a larger prospective longitudinal study of temperament and socioemotional development. Children visited the laboratory with one parent at age 2. Children’s fearful behaviors were observed during three structured tasks designed to elicit social fear (SF) (i.e., clown, stranger approach and stranger working) and coded using second-by-second microcoding system (Buss, 2011). The average score of the percentage of time children exhibited fearful behavior in each task was used. During the visit, ECG was collected during a baseline (BL) task and each SF task episode to acquire children’s cardiac physiology data. The RSA reactivity was calculated as average RSA during SF tasks minus RSA during the BL task. A negative reactivity score indicates RSA suppression, and a positive score indicates RSA augmentation. Toddlers provided saliva samples at the beginning and end of the visit. Cortisol reactivity was computed as residualized change scores comparing pre- and post-visit cortisol levels. At age 2 and 3, mothers reported children’s internalizing and externalizing behaviors using the Infant Toddler Social and Emotional Assessment (ITSEA; Carter et al., 2003).

The interactions of RSA and cortisol reactivity predicting fearful behaviors, internalizing and externalizing problems were tested separately via the PROCESS macro in SPSS (Hayes, 2013). At age 2, a marginally significant interaction was found when predicting fearful behaviors (b = 4.50, t = 1.77, p = .083), after controlling for child gender and the time difference between the two cortisol samples. The simple slope test suggested stronger positive relations between RSA augmentation and fearfulness for children with higher cortisol reactivity (Figure 1). Significant interactions were also found when predicting externalizing behaviors at age 2 (b = 0.13, t = 2.49, p = .016) and age 3 (b = 0.14, t = 2.09, p = .042), suggesting less RSA suppression was associated with higher externalizing behaviors, and these links were stronger for children with higher cortisol reactivity (Figure 2). No significant results were found when predicting internalizing behaviors at age 2 or 3.

Authors

• Liu Bai, Pennsylvania State University
  Presenting Author

• Kristin A Buss, The Pennsylvania State University
  Non-Presenting Author