The Brain Imaging for Global Health (BRIGHT) Project: Longitudinal cohort study protocol

Abstract

There is a scarcity of prospective longitudinal research targeted at early postnatal life which maps developmental pathways of early-stage processing and brain specialisation in the context of early adversity. Follow up from infancy into the one-five year age range is key, as it constitutes a critical gap between infant and early childhood studies. Availability of portable neuroimaging (functional near infrared spectroscopy (fNIRS) and electroencephalography (EEG)) has enabled access to rural settings increasing the diversity of our sampling and broadening developmental research to include previously underrepresented ethnic-racial and geographical groups in low- and middle- income countries (LMICs). The primary objective of the Brain Imaging for Global Health (BRIGHT) project was to establish brain function - using longitudinal data from mother - for-age reference curves infant dyads living in the UK and rural Gambia and investigate the association between context-associated moderators and developmental trajectories across the first two years of life in The Gambia. In total, 265 participating families were seen during pregnancy, at 7-14 days, 1-, 5-, 8-, 12-, 18- and 24-months post-partum. An additional visit is now underway at 3-5 years to assess pre-school outcomes. The majority of our Gambian cohort live in poverty, but while resource-poor in many factors they commonly experience a rich and beneficial family and caregiving context with multigenerational care and a close-knit supportive community. Understanding the impact of different factors at play in such an environment ( i.e., detrimental undernutrition versus beneficial multigenerational family support) will (i) improve the representativeness of models of general cognitive developmental pathways from birth, (ii) identify causal pathways of altered trajectories associated with early adversity at both individual and group level, and (iii) identify the context-associated moderators ( i.e. social context) that protect development despite the presence of poverty-associated challenges. This will in turn contribute to the development of targeted interventions.

Keywords: EEG; Gambia; UK; development; fNIRS; global health; infancy; longitudinal; neuroimaging; undernutrition.

Figure 1.. Summary of study visits: The Gambia.

EPDS, Edinburgh Postnatal Depression Scale; PRAS, Pregnancy-related Anxiety Scale; PSS, Perceived Stress Scale; PANAS, Positive and Negative Affect Scale; NBAS, Neonatal Behavioural Assessment Scale; SES, Socioeconomic Status; MIPH, Maternal and Infant Physical Health; fNIRS, functional near infrared spectroscopy; EEG/ERP, electroencephalography/event related potentials; SOC, Social versus Non-Social Response; HaND, Habituation and Novelty Detection; FC, Functional Connectivity Networks; WM, Working Memory; DI, Deferred Imitation task; PCI, Parent-Child Interaction; MSEL, Mullen Scales of Early Learning; LENA, Language Environment Analysis; FCI, Family Care Indicators; CDI, Communicative Development Inventory; * indicates assessments undertaken in the family’s home at the later time points.

Figure 2.. Summary of study visits: The UK.

Abbreviations: EPDS, Edinburgh Postnatal Depression Scale; PRAS, Pregnancy-related Anxiety Scale; PSS, Perceived Stress Scale; PANAS, Positive and Negative Affect Scale; NBAS, Neonatal Behavioural Assessment Scale; SES, Socioeconomic Status; MIPH, Maternal and Infant Physical Health; fNIRS, functional near infrared spectroscopy; EEG/ERP, electroencephalography/event related potentials; SOC, Social versus Non-Social Response; HaND, Habituation and Novelty Detection; FC, Functional Connectivity Networks; WM, Working Memory; DI, Deferred Imitation task; PCI, Parent-Child Interaction; MSEL, Mullen Scales of Early Learning; LENA, Language Environment Analysis; FCI, Family Care Indicators; CDI, Communicative Development Inventory; * indicates assessments undertaken in the family’s home at the later time points.

Figure 3.. Recruitment and retention of participants, The Gambia.

Figure 4.. Recruitment and retention of participants, UK.

Figure 5.. Additional caregivers at 7–14 days and 18 months of age, The Gambia.

The Figures display the make-up of secondary and tertiary caregivers at 7–14 days and 18 months of age in The Gambian cohort. Secondary caregiver; a person who looks after the infant a substantial proportion of the time. Tertiary caregiver; a person who looks after the infant ‘sometimes’. A. n=170, B. n=165, C. n=171, D. n=168.

Figure 6.. Number of languages spoken by caregivers, The Gambia.

The Figures show the proportion of primary (n=172), secondary (n=171) and tertiary (n=167) caregivers at 18 months of age, who spoke one, two or three languages.

Figure 7.. Caregivers reported at 8 and 18 months of age, UK.

The Figure shows the primary caregivers and other reported caregivers at 8 and 18 months of age for the UK cohort. 8 months of age n=46, 18 months of age n=48.

Figure 8.. Number of languages heard in the home by infants at 18 months, UK.

Figure 9.. Percent of English heard by UK infants across age points.

Note: While the majority of families completed this questionnaire antenatally (95.2%), the proportion of families who provided this information at 8 – 24 months dropped significantly to 62.9 – 74.2% complete datasets from the full cohort. This was due either to families withdrawing from the study at 18 – 24 months or missing data within the demographic questionnaire.

Figure 10.. Distribution of participant age (in days) in the BRIGHT Kids follow up, The Gambia.