White matter microstructure predicts individual differences in infant fear (But not anger and sadness)

We examine neural correlates of discrete expressions of negative emotionality in infants to determine whether the microstructure of white matter tracts at 1 month of age foreshadows the expression of specific negative emotions later in infancy. Infants (n = 103) underwent neuroimaging at 1-month, and mothers reported on infant fear, sadness, and anger at 6, 12, and 18 months using the Infant Behavior Questionnaire-Revised. Levels and developmental change in fear, sadness, and anger were estimated from mother reports. Relations between MRI and infant emotion indicated that 1-month white matter microstructure was differentially associated with level and change in infant fear, but not anger or sadness, in the left stria terminalis (p < 0.05, corrected), a tract that connects frontal and tempo-parietal regions and has been implicated in emerging psychopathology in adults. More relaxed constraints on significance (p < 0.10, corrected) revealed that fear was associated with lower white matter microstructure bilaterally in the inferior portion of the stria terminalis and regions within the sagittal stratum. Results suggest the neurobehavioral uniqueness of fear as early as 1 month of age in regions that are associated with potential longer-term outcomes. This work highlights the early neural precursors of fearfulness, adding to literature explaining the psychobiological accounts of affective development.

Highlights

• Expressions of infant fear and anger, but not sadness, increase from 6 to 18 months of age.
• Early neural architecture in the stria terminalis is related to higher initial levels and increasing fear in infancy.
• After accounting for fear, anger and sadness do not appear to be associated with differences in early white matter microstructure.
• This work identifies early neural precursors of fearfulness as early as 1-month of age.

     

Birth order,stimulating environment,and maternal factors in developmental outcomes: A longitudinal Mexican study

This study longitudinally examined the interplay between birth-order and well-known risk factors in impoverished environments such as inadequate environmental stimulation, low maternal education, and young maternal age in children from birth to 36 months. In the developmental motor domain, the effect of the stimulating environment over time, favored first-borns. In the adaptive domain, maternal education privileged first-born boys. In language development, first-borns reached higher scores over time than laterborn identifying a positive impact of stimulation. In the personal-social domain, firstborns obtained higher averages overall, but stratified models revealed that later-borns reached the first-borns scores as maternal age increased.     

Cross-cultural differences in temperament: Comparing paternal ratings of US and Dutch infants

This study conducted longitudinal comparisons of US and Dutch paternal ratings of temperament, measured via the Infant Behaviour Questionnaire-Revised, at 4 months (US n = 99; Dutch n = 127) and 12 months (US n = 66; Dutch n = 112) of age. US fathers rated their infant higher in the broad temperament trait Surgency, and its subscales vocal reactivity, high-intensity pleasure, and activity level. US fathers also rated their infants higher in negative emotionality, and its subscales of sadness, distress to limitations, and fear. Dutch infants received higher ratings in falling reactivity. Though the cultures did not differ in ratings of Orienting/regulatory capacity, US infants were higher on the subscale duration of orienting, and lower in soothability. Significant culture-by-age and culture-by-gender interactions were also noted. Overall, results are largely consistent with those reported for Dutch mothers and speak to considerable differences in early temperament development between cultures viewed as largely similar because of their Western/individualistic orientations.