Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Erin Tully


A growing body of theory and research has implicated cardiac vagal activity, indexed by measures of respiratory sinus arrhythmia (RSA), in the emotion dysregulation underlying internalizing psychopathology; however, the majority of these studies are with adolescent or adult samples. Middle childhood is a critical period for children’s social emotional development as peer relationships become increasingly important and related to children’s psychological adjustment, and it immediately precedes the increases in rates of internalizing symptoms observed in adolescence. Findings suggest that children with internalizing problems may exhibit a reduced capacity for emotion regulation and some tend to be physiologically hyper-reactive to others’ sadness while others tend to be disengaged and hypo-reactive. Thus, I predict that high internalizing symptoms will be associated with low resting RSA and both excessive and blunted RSA reactivity to sadness (i.e., a positive quadratic association). Less is known about how children with internalizing problems react physiologically to positive emotions, such as happiness, or recover after happy or sad situations. Some studies suggest that internalizing problems may be associated with sustained physiological arousal following sadness (low RSA recovery), physiological hypo-reactivity to happiness (blunted RSA reactivity), and poor sustainability of the physiological effects of happiness (high RSA recovery). Electrocardiograms were recorded from 114 children (ages 7-11) while they watched a series of happy-, sad-, and neutral-valence emotional videos featuring other children. Parents reported on children’s level of internalizing symptoms. Results of the current study add to the extant literature supporting low resting RSA and excessive, but not blunted, RSA reactivity to sadness as predictors of internalizing problems during middle childhood. In contrast, blunted RSA reactivity to sadness, RSA reactivity to happiness and RSA recovery after happiness and sadness were not associated with internalizing problems during this time. These results suggest that internalizing psychopathology in middle childhood is more closely linked to an individual’s trait-like capacity for physiological emotion regulation and dysregulation of withdrawal-motivation based emotions (sadness) in the moment than dysregulation of approach-based emotions (happiness). Future longitudinal studies are needed to better understand the developmental progression of internalizing liabilities from childhood to adolescence.

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Available for download on Thursday, April 21, 2022