Xie, W., Mallin, B.A., & Richards, J.E. (in press). Development of brain functional connectivity and its relation to infant sustained attention in the first year of life. Developmental Science.
The study of brain functional connectivity is crucial to understanding the neural mechanisms underlying the improved behavioral performance and amplified ERP responses observed during infant sustained attention. Previous investigations on the development of functional brain connectivity during infancy are primarily confined to the use of functional and structural MRI techniques. The current study examined the relation between infant sustained attention and brain functional connectivity and their development during infancy with high-density EEG recordings. Fifty-nine infants were tested at six (N = 15), eight (N =14), ten (N = 17), and twelve (N = 13) months. Infant sustained attention was defined by measuring infant heart rate changes during infants’ looking. Functional connectivity was estimated from the electrodes on the scalp and with reconstructed cortical source activities in brain regions. 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 within brain networks and the graph theory measures of path length and clustering coefficient were found to increase with age. The characteristic of small-worldness was found for infants at 6 and 8 months in the alpha and beta bands. These findings suggest that infant sustained attention is accompanied by distinct patterns of brain functional connectivity. The current findings also provide convergent evidence for the rapid development of functional connectivity in brain networks during infancy.