Latent State-Trait Modeling: A New Tool to Refine Temperament Methodology

A preliminary investigation of epigenome-wide DNA methylation and temperament during infancy

This study provides preliminary evidence for an epigenetic architecture of infant temperament. At 12 months of age, blood was collected and assayed for DNA methylation and maternally reported infant temperament was assessed using the Infant Behavior Questionnaire in 67 mother-infant dyads. Epigenome-wide analyses showed that the higher order temperament dimensions Surgency and Negative Affect were associated with DNA methylation. The epigenetic signatures of Surgency and Negative Affect were situated at genes involved in synaptic signaling and plasticity. Although replication is required, these results are consistent with a biologically based model of temperament, create new avenues for hypothesis-driven research into epigenetic pathways that underlie individual differences in temperament, and demonstrate that infant temperament has a widespread epigenetic signature in the methylome.

The effect of maternal depression on mental representations and child negative affect

BACKGROUND

Maternal depression is a widely recognized public health concern with significant implications for child functioning, including the development of negative child affect and risk for later depression. Negative mental representations may partially account for the association between maternal depression and child negative affect.

METHODS

The effect of depression on low-income mothers' representations of their child, self, and mother was assessed via Expressed Emotion (EE) during Five-Minute Speech Samples. Direct and indirect pathways between maternal depression, EE, and child negative affect were examined. Mothers (M = 24 years old) who had experienced a major depressive episode (n = 144) since child's birth, non-depressed comparison mothers (n = 62), and their children participated.

RESULTS

Examination of between-group differences revealed that depressed mothers had higher levels of overall self EE. Trend results also suggest depressed mothers may have higher overall EE toward their children and their own mothers. Novel coding systems for EE toward self (Identity and Depressotypic Cognitions) and EE toward mother (Source of Concrete Support and Resolution of Past Adversity) were also developed and tested. A significant indirect relation was found between maternal baseline depression and child negative affect at 26 months via the mother's level of EE-Criticism of her mother.

LIMITATIONS

Certain EE subcodes may need to be adapted for young children and high-risk, low-income participants.

CONCLUSIONS

Findings highlights the importance of relational interventions that focus on maternal representations for women with depression and their children.

Frontal electroencephalogram (EEG) asymmetry reactivity: Exploring changes from baseline to still face procedure response

Electroencephalogram (EEG) asymmetry has been widely studied across the lifespan, with multiple studies conducted in infancy. However, few have investigated frontal EEG asymmetry in the context of emotional-eliciting tasks, controlling for baseline to focus on an experimental episode response. The present study was designed to address this gap in research, predicting frontal EEG asymmetry response in the context of the Still Face procedure (SFP), examining mother–infant interaction quality and infant temperament attributes as potential contributors. Moderation by infant temperament was also considered. Results indicated that intensity and tone of parent–child interactions as well as Surgency/Positive Affectivity (and component scales of Approach and Activity Level) predicted frontal EEG asymmetry during SFP, controlling for baseline. Importantly, moderation was noted for Surgency/Positive Affectivity and its Approach component, reflected in significant interaction terms and follow-up simple slope tests. That is, the effect of intensity in mother–infant interactions was qualified by child overall surgency, and approach more specifically – infants demonstrating higher levels of Surgency/Positive Affectivity and Approach in particular were protected from the right frontal EEG response to SFP noted in the context of intense concurrent exchanges with mothers.