A Preliminary Exploration of Default Mode Network in Normal Children - A fMRI Study with Flashing Checkerboard Stimulation

Objective: To study whether the activity of default mode network in children shows anatomical consistency with the adult, and if not, then find out the difference and possible reason. Methods: Ten healthy children underwent an axial T₁-weighted FLAIR scan and two fMRI scans with different flashing checkerboard stimulation. After data preprocessing and statistical analysis, pixel level t-test was used to screening deactivated brain regions. Results: Posterior cingulate/precuneous, inferior parietal cortex, thalamus and middle tempral gyrus showed consistent deactivation throughout the whole process. Some other brain areas, such as superior and medial frontal cortex, fusiform gyrus and insula only deactivated in partial stimuli. Conclusions: Pediatric resting-state brain activity showed both commonalities and disparities with adults. The default mode network anatomically formed at a relatively early age, but a stable functional connectivity is strengthened gradually and formed later. Fusiform gyrus's key role in color perception was confirmed. Thalamus showed obvious deactivation. We suggest it may be partially due to children's immature brain and the intermediary brain tissue is more important.