Cortical specialisation to social stimuli from the first days to the second year of life: A rural Gambian cohort.

Brain and nervous system development in human infants during the first 1000days (conception to two years of age) is critical, and compromised development during this time (such as from under nutrition or poverty) can have life-long effects on physical growth and cognitive function. Cortical mapping of cognitive function during infancy is poorly understood in resource-poor settings due to the lack of transportable and low-cost neuroimaging methods. Having established a signature cortical response to social versus non-social visual and auditory stimuli in infants from 4 to 6 months of age in the UK, here we apply this functional Near Infrared Spectroscopy (fNIRS) paradigm to investigate social responses in infants from the first postnatal days to the second year of life in two contrasting environments: rural Gambian and urban UK. Results reveal robust, localized, socially selective brain responses from 9 to 24 months of life to both the visual and auditory stimuli. In contrast at 0-2 months of age infants exhibit non-social auditory selectivity, an effect that persists until 4-8 months when we observe a transition to greater social stimulus selectivity. These findings reveal a robust developmental curve of cortical specialisation over the first two years of life.

Using fNIRS to Study Working Memory of Infants in Rural Africa.

A pilot study was conducted to assess the feasibility of using fNIRS as an alternative to behavioral assessments of cognitive development with infants in rural Africa. We report preliminary results of a study looking at working memory in 12-16-month-olds and discuss the benefits and shortcomings for the potential future use of fNIRS to investigate the effects of nutritional insults and interventions in global health studies.