An initial investigation of neonatal neuroanatomy, caregiving, and levels of disorganized behavior.

Attachment disorganization is a risk factor for difficulties in attention, social relationships, and mental health. Conceptually, attachment disorganization may indicate a breakdown in fear regulation resulting from repeated exposure to frightening maternal care. In addition, past research has examined the influence of stress-inducing contextual factors and/or child factors upon the development of disorganization. However, no past work has assessed whether infant neuroanatomy, important to stress regulation, moderates the association between maternal care and levels of disorganized behavior. Here, utilizing data from a subsample of 82 dyads taking part in the "Growing Up in Singapore towards Healthy Outcomes" (GUSTO) cohort, we assessed the prediction from maternal sensitive caregiving at 6 mo and levels of attachment disorganization at 1.5 y, as moderated by hippocampal and amygdala volume determined within the first 2 weeks of life. Results indicate a significant interaction between neonatal left hippocampal volume and maternal sensitivity upon levels of disorganized behavior. Although these results require substantiation in further research, if replicated, they may enable new strategies for the identification of processes important to child mental health and points for intervention. This is because neonatal neuroanatomy, as opposed to genetic variation and sociodemographic risk, may be more directly linked to stress responses within individuals.

Maternal sensitivity during infancy and the regulation of startle in preschoolers.

Caregiving insensitivity and fear dysregulation predict anxiety symptoms in children. It is unclear, however, whether sensitive parental care during infancy predicts fear regulation later in childhood. To address this question, we asked whether observed maternal sensitivity, measured at 6 months, predicts 42-month-old children's laboratory-induced fear responses (n=213) during a fear-eliciting episode. We predicted that higher levels of maternal sensitivity would be associated with greater fear regulation. We operationalized fear regulation as decreases in fear over repeated trials of a novel, potentially frightening, stimulus. Two aspects of fear responses were considered: expressed fear and startle. Expressed fear scores did not decrease over time but children exhibited less startle behavior in the second half of the task. Maternal sensitivity predicted this startle attenuation across trials. These findings highlight the contribution of maternal sensitivity during infancy to the development of fear regulation in early childhood, further suggesting its influence on offspring anxiety problems.

The role of ethnicity and socioeconomic status in Southeast Asian mothers' parenting sensitivity.

Past research indicates that socioeconomic status (SES) accounts for differences in sensitivity across ethnic groups. However, comparatively little work has been conducted in Asia, with none examining whether ethnicity moderates the relation between SES and sensitivity. We assessed parenting behavior in 293 Singaporean citizen mothers of 6-month olds (153 Chinese, 108 Malay, 32 Indian) via the Maternal Behavioral Q-Sort for video interactions. When entered into the same model, SES (F(1,288) = 17.777, p < .001), but not ethnicity, predicted maternal sensitivity (F(2,288) = .542, p = .582). However, this positive relation between SES and sensitivity was marginally moderated by ethnicity. SES significantly positively predicted sensitivity in Chinese, but not Malay dyads. Within Indian dyads, SES marginally positively predicted sensitivity only when permanent residents were included in analyses. We discuss the importance of culture on perceived SES-associated stress. However, because few university-educated Malays participated, we also consider whether university education, specifically, positively influences sensitivity.

The influence of CHRNA4, COMT, and maternal sensitivity on orienting and executive attention in 6-month-old infants.

Despite claims concerning biological mechanisms sub-serving infant attention, little experimental work examines its underpinnings. This study examines how candidate polymorphisms from the cholinergic (CHRNA4 rs1044396) and dopaminergic (COMT rs4680) systems, respectively indicative of parietal and prefrontal/anterior cingulate involvement, are related to 6-month-olds' (n=217) performance during a visual expectation eye-tracking paradigm. As previous studies suggest that both cholinergic and dopaminergic genes may influence susceptibility to the influence of other genetic and environmental factors, we further examined whether these candidate genes interact with one another and/or with early caregiving experience in predicting infants' visual attention. We detected an interaction between CHRNA4 genotype and observed maternal sensitivity upon infants' orienting to random stimuli and a CHRNA4-COMT interaction effect upon infants' orienting to patterned stimuli. Consistent with adult research, we observed a direct effect of COMT genotype on anticipatory looking to patterned stimuli. Findings suggest that CHRNA4 genotype may influence susceptibility to other attention-related factors in infancy. These interactions may account for the inability to establish a link between CHRNA4 and orienting in infant research to date, despite developmental theorizing suggesting otherwise. Moreover, findings suggest that by 6months, dopamine, and relatedly, the prefrontal cortex/anterior cingulate, may be important to infant attention.

Back to basics: a bilingual advantage in infant visual habituation.

Comparisons of cognitive processing in monolinguals and bilinguals have revealed a bilingual advantage in inhibitory control. Recent studies have demonstrated advantages associated with exposure to two languages in infancy. However, the domain specificity and scope of the infant bilingual advantage in infancy remains unclear. In the present study, 114 monolingual and bilingual infants were compared in a very basic task of information processing-visual habituation-at 6 months of age. Bilingual infants demonstrated greater efficiency in stimulus encoding as well as in improved recognition memory for familiar stimuli as compared to monolinguals. Findings reveal a generalized cognitive advantage in bilingual infants that is broad in scope, early to emerge, and not specific to language.

Analysis of Item-Level Bias in the Bayley-III Language Subscales: The Validity and Utility of Standardized Language Assessment in a Multilingual Setting.

Purpose: The purpose of this study was to improve standardized language assessments among bilingual toddlers by investigating and removing the effects of bias due to unfamiliarity with cultural norms or a distributed language system. Method: The Expressive and Receptive Bayley-III language scales were adapted for use in a multilingual country (Singapore). Differential item functioning (DIF) was applied to data from 459 two-year-olds without atypical language development. This involved investigating if the probability of success on each item varied according to language exposure while holding latent language ability, gender, and socioeconomic status constant. Associations with language, behavioral, and emotional problems were also examined. Results: Five of 16 items showed DIF, 1 of which may be attributed to cultural bias and another to a distributed language system. The remaining 3 items favored toddlers with higher bilingual exposure. Removal of DIF items reduced associations between language scales and emotional and language problems, but improved the validity of the expressive scale from poor to good. Conclusions: Our findings indicate the importance of considering cultural and distributed language bias in standardized language assessments. We discuss possible mechanisms influencing performance on items favoring bilingual exposure, including the potential role of inhibitory processing.