Longitudinal Assessments of Functional Near-Infrared Spectroscopy Background Functional Connectivity in Low- and Middle-Income Infants During a Social Cognition Task

• Published in: Journal of experimental psychology. General 2024-03, Vol.153 (3), p.798-813
• Main Authors: Di Lonardo Burr, Sabrina M., Pirazzoli, Laura, Dopierała, Aleksandra W., Bejjanki, Vikranth R., Nelson, Charles A., Emberson, Lauren L.
• Format: Article
• Language: English
• Subjects: Adversity; Babies; Brain; Brain Connectivity; Child development; Cognitive ability; Human; Infant Development; Lower Income Level; Middle Income Level; Social Cognition; Social Processes; Spectroscopy
• ISSN: 0096-3445; 1939-2222
• DOI: 10.1037/xge0001531

Shortly after birth, human infants demonstrate behavioral selectivity to social stimuli. However, the neural underpinnings of this selectivity are largely unknown. Here, we examine patterns of functional connectivity to determine how regions of the brain interact while processing social stimuli and how these interactions change during the first 2 years of life. Using functional near-infrared spectroscopy (fNIRS), we measured functional connectivity at 6 (n = 147) and 24 (n = 111) months of age in infants from Bangladesh who were exposed to varying levels of environmental adversity (i.e., low- and middle-income cohorts). We employed a background functional connectivity approach that regresses out the effects of stimulus-specific univariate responses that are believed to affect functional connectivity. At 6 months, the two cohorts had similar fNIRS patterns, with moderate connectivity estimates for regions within and between hemispheres. At 24 months, the patterns diverged for the two cohorts. Global (brain-wide) connectivity estimates increased from 6 to 24 months for the low-income cohort and decreased for the middle-income (MI) cohort. In particular, connectivity estimates among regions of interest within the right hemisphere decreased for the MI cohort, providing evidence of neural specialization by 2 years of age. These findings provide insights into the impact of early environmental influences on functional brain development relevant to the processing of social stimuli. Public Significance Statement We investigated patterns of brain connectivity during a social cognition task for two cohorts of infants (low income and middle income) from Bangladesh at 6 and 24 months of age. We found similar patterns of connectivity at 6 months, but at 24 months substantial differences were observed between the two cohorts, such that only the middle-income cohort showed evidence of specialization. Our findings reveal developmental differences in the networks engaged in social perception and the manner in which early life experiences impact these networks.