​Neuroimage. Available online 28 April 2017
Brain maturation during the preschool period (2-6 years) is understudied and typical functional brain development is not well explained. Understanding brain development during the preschool years is critical in order to map human brain maturation, and also inform proper identification of and interventions for brain disorders. The aim of this study was to identify age-related changes in brain function in healthy preschool children using functional magnetic resonance imaging (fMRI). We examined 77 fMRI scans from a total of 44 healthy children aged 2.5-5.8 years. The data collected was used to investigate functional connectivity, which measures how brain regions communicate with one another. We were interested in looking at connectivity both between neighbouring brain regions (local connectivity) and across the brain (global connectivity).
The results of this work show age-related changes in functional connectivity both at the local and global levels. Local connectivity increased with age in brain regions involved in self-regulation and attention control. Increased connections in local brain areas and across the brain were seen in a region responsible for self-reference and theory of mind. In addition, an area associated with language function had decreased local connectivity and increased global connectivity with age. This suggests a shift to a more global arrangement, and is likely related to language development. Finally, the parietal and temporal regions showed a shift from global connectivity to local connectivity, which may be connected to development of memory, facial recognition and other cognitive functions. Evidently, the preschool years represent a period of important functional brain development and continuing to investigate questions surrounding maturation during this time is imperative.