The evolution of spatial patterns of brain activity during development and their role in the functional specialization of brain networks

The development of functionally specialized brain networks allows the emergence and improvement of cognitive abilities. This specialization emerges in part from the interactions between brain regions through changes in the temporal organization of their brain activity. In addition, it is now well assumed that the functioning of mature brain networks also depends on the spatial organization of their brain activity. However, how this spatial organization is formed during development remains unknown, nor do we know whether it contributes to the functional specialization of brain networks. This study attempts to answer these questions by examining the developmental changes in the spatial patterns of brain activity of the functional brain network involved in the theory of mind (capacity to understand others' mental states). Using fMRI dataset from the cross-sectional study of Richardson et al. (2018), our findings show for the first time that the brain regions of this network show increasingly similar spatial patterns of activity. Furthermore, this increasing spatial similarity is associated with improved children's performance in a theory-of-mind task. We propose that the increasing similarity between spatial brain activity patterns during development has important implications for understanding the functional specialization of brain networks.