Development of Brain Functional Connectivity and Its Relation To Infant Sustained Attention In The First Year Of Life

This dissertation project studies the development of infant sustained attention and its relation to brain functional connectivity from 6 to 12 months of age. Chapter 1 is a general introduction of the dissertation project. Chapter 2 is a review of the existing literature on the development of infant sustained attention. This chapter includes theories on infant sustained attention and findings from studies using behavioral and psychophysiological measurements. Chapter 3 is a review of the recent advances made in the study of the development of functional connectivity in brain networks. This chapter covers some empirical evidence for the development of functional networks using EEG and fMRI techniques. In Chapter 4 I introduce an experiment that examined the potential relation between infant sustained attention and distinct patterns of brain functional connectivity suggested by the literature reviewed in Chapter 2 and 3. The sample of the experiment consisted of 59 participants aged from 6 to 12 months. Infant sustained attention and inattention were defined by measuring infant heart rate changes. Functional connectivity was estimated with high-density EEG recordings from the electrodes on the scalp and with the reconstructed cortical source activities in brain regions. Graph theory measures were applied to give a broader view of the architecture of brain functional networks. It was found that infant sustained attention was accompanied by attenuated functional connectivity in the dorsal attention and default mode networks in the alpha band. Graph theory analyses showed that there was an increase in path length and a decrease in clustering coefficient during infant sustained attention. The functional connectivity in brain networks and the graph theory measures of path length and clustering coefficient were found to increase with age. The small-worldness was found for infants at 6 and 8 months in the alpha and beta bands. These findings lend support to the hypothesis of the relation between the distinct patterns of brain functional connectivity and infant sustained attention. The current findings also provide convergent evidence for the rapid development of functional connectivity in brain networks during infancy

EEG phase-amplitude coupling strength and phase preference: association with age over the first three years after birth

Phase-amplitude coupling (PAC), the coupling of the phase of slower electrophysiological oscillations with the amplitude of faster oscillations, is thought to facilitate dynamic integration of neural activity in the brain. Although the brain undergoes dramatic change and development during the first few years of life, how PAC changes through this developmental period has not been extensively studied. Here, we examined PAC through electroencephalography (EEG) data collected during an awake, eyes-open EEG collection paradigm in 98 children between the ages of three months and three years. We employed non-parametric clustering methods to identify areas of significant PAC across a range of frequency pairs and electrode locations, and examined how PAC strength and phase preference develops in these areas. We found that PAC, primarily between the α-β and γ frequencies, was positively correlated with age from early infancy to early childhood (p = 2.035 × 10-6). Additionally, we found γ over anterior electrodes coupled with the rising phase of the α-β waveform, while γ over posterior electrodes coupled with the falling phase of the α-β waveform; this regionalized phase preference became more prominent with age. This opposing trend may reflect each region's specialization toward feedback or feedforward processing, respectively, suggesting opportunities for back translation in future studies.P50 HD105351 - NICHD NIH HHS; R21 DC008637 - NIDCD NIH HHSPublished versio

The construction of MRI brain/head templates for Chinese children from 7 to 16 years of age

Population-specific brain templates that provide detailed brain information are beneficial to both structural and functional neuroimaging research. However, age-specific MRI templates have not been constructed for Chinese or any Asian developmental populations. This study developed novel T1-weighted average brain and head templates for Chinese children from 7 to 16 years of age in two-year increments using high quality magnetic resonance imaging (MRI) and well-validated image analysis techniques. A total of 138 Chinese children (51 F/87 M) were included in this study. The internally and externally validated registrations show that these Chinese age-specific templates fit Chinese children's MR images significantly better than age-specific templates created from U.S. children, or adult templates based on either Chinese or North American adults. It implies that age-inappropriate (e.g., the Chinese56 template, the US20–24 template) and nationality-inappropriate brain templates (e.g., U.S. children's templates, the US20–24 template) do not provide optimal reference MRIs for processing MR brain images of Chinese pediatric populations. Thus, our age-specific MRI templates are the first of the kind and should be useful in neuroimaging studies with children from Chinese or other Asian populations. These templates can also serve as the foundations for the construction of more comprehensive sets of nationality-specific templates for Asian developmental populations. These templates are available for use in our database

Neural correlates of facial emotion processing in infancy

In the present study we examined the neural correlates of facial emotion processing in the first year of life using ERP measures and cortical source analysis. EEG data were collected cross-sectionally from 5- (N = 49), 7- (N = 50), and 12-month-old (N = 51) infants while they were viewing images of angry, fearful, and happy faces. The N290 component was found to be larger in amplitude in response to fearful and happy than angry faces in all posterior clusters and showed largest response to fear than the other two emotions only over the right occipital area. The P400 and Nc components were found to be larger in amplitude in response to angry than happy and fearful faces over central and frontal scalp. Cortical source analysis of the N290 component revealed greater cortical activation in the right fusiform face area in response to fearful faces. This effect started to emerge at 5 months and became well established at 7 months, but it disappeared at 12 months. The P400 and Nc components were primarily localized to the PCC/Precuneus where heightened responses to angry faces were observed. The current results suggest the detection of a fearful face in infants' brain can happen shortly (~200-290 ms) after the stimulus onset, and this process may rely on the face network and develop substantially between 5 to 7 months of age. The current findings also suggest the differential processing of angry faces occurred later in the P400/Nc time window, which recruits the PCC/Precuneus and is associated with the allocation of infants' attention

Infants’ neural responses to emotional faces are related to maternal anxiety

BackgroundPostnatal maternal anxiety is common (estimates as high as 40% prevalence) and is associated with altered mother-infant interactions (e.g., reduced maternal emotional expression and engagement). Neural circuitry supporting infants' face and emotion processing develops in their first year. Thus, early exposure to maternal anxiety may impact infants' developing understanding of emotional displays. We examine whether maternal anxiety is associated with individual differences in typically developing infants' neural responses to emotional faces.MethodsOne hundred and forty two mother-infant dyads were assessed when infants were 5, 7, or 12 months old. Infants' electroencephalographic (EEG) data were recorded while passively viewing female happy, fearful, and angry faces. Three event-related potential (ERP) components, each linked to face and emotion processing, were evaluated: NC, N290, and P400. Infant ERP amplitude was related to concurrent maternal-report anxiety assessed with the Spielberger State-Trait Anxiety Inventory (Trait form).ResultsGreater maternal anxiety predicted more negative NC amplitude for happy and fearful faces in left and mid-central scalp regions, beyond covarying influences of maternal depression symptoms, infant negative emotionality, and infant age.ConclusionsPostnatal maternal anxiety is related to infants' neural processing of emotional expressions. Infants of mothers endorsing high trait anxiety may need additional attentional resources to process happy and fearful faces (expressions less likely experienced in mother-infant interactions). Future research should investigate mechanisms underlying this association, given possibilities include experiential, genetic, and prenatal factors

Association of psychosocial adversity and social information processing in children raised in a low-resource setting: an fNIRS study.

Social cognition skills and socioemotional development are compromised in children growing up in low SES contexts, however, the mechanisms underlying this association remain unknown. Exposure to psychosocial risk factors early in life alters the child's social milieu and in turn, could lead to atypical processing of social stimuli. In this study, we used functional Near Infrared Spectroscopy (fNIRS) to measure cortical responses to a social discrimination task in children raised in a low-resource setting at 6, 24, and 36 months. In addition, we assessed the relation between cortical responses to social and non-social information with psychosocial risk factors assessed using the Childhood Psychosocial Adversity Scale (CPAS). In line with previous findings, we observed specialization to social stimuli in cortical regions in all age groups. In addition, we found that risk factors were associated with social discrimination at 24 months (intimate partner violence and verbal abuse and family conflict) and 36 months (verbal abuse and family conflict and maternal depression) but not at 6 months. Overall, the results show that exposure to psychosocial adversity has more impact on social information processing in toddlerhood than earlier in infancy