The Impact of Caregiving on the Association Between Infant Emotional Behavior and Resting State Neural Network Functional Topology

Longitudinal associations between mother-child attachment security in toddlerhood and white matter microstructure in late childhood: a preliminary investigation

Early childhood experiences are considered to influence the strength and effectiveness of neural connections and thus the development of brain connectivity. As one of the most pervasive and potent early relational experiences, parent-child attachment is a prime candidate to account for experience-driven differences in brain development. Yet, knowledge of the effects of parent-child attachment on brain structure in typically developing children is scarce and largely limited to grey matter, whereas caregiving influences on white matter (i.e. neural connections) have seldom been explored. This study examined whether normative variation in mother-child attachment security predicts white matter microstructure in late childhood and explored associations with cognitive-inhibition. Mother-child attachment security was assessed using home observations when children (N = 32, 20 girls) were 15 and 26 months old. White matter microstructure was assessed using diffusion magnetic resonance imaging when children were 10 years old. Child cognitive-inhibition was tested when children were 11 years old. Results revealed a negative association between mother-toddler attachment security and child white matter microstructure organization, which in turn related to better child cognitive-inhibition. While preliminary given the sample size, these findings add to the growing literature that suggests that rich and positive experiences are likely to decelerate brain development.

Postnatal maternal distress, infant subcortical brain macrostructure and emotional regulation

BACKGROUND

Maternal distress is associated with an increased risk for adverse emotional development in infants, including difficulties with emotion regulation. Prenatal maternal distress has been associated with alterations in infant brain development. However, less is known about these associations with postnatal maternal distress, despite this being an important modifiable risk factor that can promote healthy brain development and emotional outcomes in infants.

METHODS & RESULTS

Infants underwent magnetic resonance imaging (MRI) and mothers completed standardized questionnaires concerning their levels of perceived distress 2-5 months postpartum. Infant emotion regulation was assessed at 8-11 months via maternal report. When examining the associations between maternal distress and infant macrostructure, maternal anxiety was associated with infant right pallidum volumes. Increased display of negative emotions at 8-11 months of age was associated with smaller hippocampal volumes and this association was stronger in girls than boys.

CONCLUSION

Findings suggest that postnatal maternal distress may be associated with early infant brain development and emphasize the importance of maternal mental health, supporting previous work. Furthermore, macrostructural properties of infant subcortical structures may be further investigated as potential biomarkers to identify infants at risk of adverse emotional outcomes.

Origins of Anhedonia in Childhood and Adolescence

Anhedonia reflects a reduced ability to engage in previously pleasurable activities and has been reported in children as young as 3 years of age. It manifests early and is a strong predictor of psychiatric disease onset and progression over the course of development and into adulthood. However, little is known about its mechanistic origins, particularly in childhood and adolescence. In this chapter, we provide a socio-cognitive model of the development of anhedonia. This model is substantiated by past literature presented in this chapter to account for how the individual trajectories of emotion knowledge, autobiographical memory, and self-concept representations contribute to the onset, persistence, and progression of anhedonia from early childhood through adolescence.

Infant social interactions and brain development: A systematic review

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Associations between caregiver-infant behaviours during social interactions and brain development outcomes were investigated.

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Caregivers' and infants' behaviours in interactions related to children’s structural, functional and connectivity measures.

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Concurrent associations between behavioural and brain measures were apparent as early as three months postnatally.

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Long-term associations between behaviours in early interactions and brain development outcomes were observed decades later.

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Individual differences in early interactions and associated brain development is an important avenue for further research.

From birth, interactions with others are an integral part of a person’s daily life. In infancy, social exchanges are thought to be critical for optimal brain development. This systematic review explores this association by drawing together infant studies that relate adult-infant behaviours – coded from their social interactions - to children’s brain measures collected during a neuroimaging session in infancy, childhood, adolescence or adulthood. In total, we identified 55 studies that explored associations between infants’ social interactions and neural measures. These studies show that several aspects of caregiver-infant behaviours are associated with, or predict, a variety of neural responses in infants, children and adolescents. The presence of both concurrent and long-term associations - some of which are first observed just a few months postnatally and extend into adulthood - open an important research avenue and motivate further longitudinal studies.

Patterns of Infant Amygdala Connectivity Mediate the Impact of High Caregiver Affect on Reducing Infant Smiling: Discovery and Replication

BACKGROUND

Behavioral research indicates that caregiver mood disorders and emotional instability in the early months following childbirth are associated with lower positive emotionality and higher negative emotionality in infants, but the neural mechanisms remain understudied.

METHODS

Using resting-state functional connectivity as a measure of the functional architecture of the early infant brain, we aimed to determine the extent to which connectivity between the amygdala, a key region supporting emotional learning and perception, and large-scale neural networks mediated the association between caregiver affect and anxiety and early infant negative emotionality and positive emotionality. Two samples of infants (first sample: n = 58; second sample: n = 31) 3 months of age underwent magnetic resonance imaging during natural sleep.

RESULTS

During infancy, greater resting-state functional connectivity between the amygdala and the salience network and, to a lesser extent, lower amygdala and executive control network resting-state functional connectivity mediated the effect of greater caregiver postpartum depression and trait anxiety on reducing infant smiling (familywise error-corrected p < .05). Furthermore, results from the first sample were replicated in the second, independent sample, to a greater extent for caregiver depression than for caregiver anxiety.

CONCLUSIONS

We provide evidence of early objective neural markers that can help identify infants who are more likely to be at risk from, versus those who might be protected against, the deleterious effects of caregiver depression and anxiety and reduced positive emotionality.

Gut microbiota composition is associated with temperament traits in infants

BACKGROUND

One of the key behavioral phenotypes in infancy are different temperament traits, and certain early life temperament traits have been shown to precede later mental health problems. Differences in the gut microbiota composition (GMC) have been suggested to link with neurodevelopment. For example, toddler temperament traits have been found to associate with differences in GMC; however, studies in infants are lacking although infancy is a rapid period of neurodevelopment as well as GM development. Thus, we aimed to investigate association between infant GMC and temperament.

METHODS

The study population (n = 301, 53% boys) was drawn from the FinnBrain Birth Cohort Study. Stool samples were collected from the 2.5-month-old infants and sequenced with 16S Illumina MiSeq platform. GMC taxonomic composition (at Genus and OTU level), observed sample clusters, diversity and richness were investigated in relation to the maternal reports of Infant Behavior Questionnaire -Revised (IBQ-R) at the age of 6 months.

RESULTS

Three sample clusters (Bifidobacterium/Enterobacteriaceae, Bacteroides, V. Dispar) based on GMC were identified, of which Bifidobacterium/Enterobacteriaceae-cluster presented with higher scores on the IBQ-R main dimension regulation and its subscale duration of orienting compared to Bacteroides-cluster. The clusters associated with temperament in a sex-dependent manner. The IBQ-R main dimension surgency (positive emotionality) was associated positively both with genus Bifidobacterium and Streptococcus. Alpha diversity had a negative association with negative emotionality and fear reactivity.

CONCLUSION

This is the first study demonstrating associations, but not causal connections, between GMC and temperament in young infants in a prospective design.