Task-based fMRI study of activation in the brain network: A seed-based functional connectivity analysis

Background: Task-based functional magnetic resonance imaging (fMRI) is an effective method for noninvasively studying brain activity.We aim to find representative brain areas of the swallowing movement and compare the functional connectivity differences in these areas.Materials and Methods: A total of 23 participants were recruited to undergo task-based fMRI scans.Subject-level statistical analysis and group -level activation analysis were conducted using SPM12.Seed-based Functional Connectivity (FC) analyses were conducted to construct FC in brain level.We used two -sample t-test to identify distinctive FC patterns in various seeds.The relationship between FC values and swallowing frequency was also explored.Results: In experiment I, group-level activation patterns were observed in 30-second saliva swallowing trial task, but not in 18s-on task.Two sample t-tests showed that the seed located in right pericentral area (Seed3) had significantly more intensive FC than that located in cingulum (Seed5) with left postcentral gyrus, the seed located in left pericentral area(Seed4) had significantly more intensive FC than those located in cerebellum(Seed1,2) or in Seed5 with right postcentral gyrus, Seed5 had significantly more intensive FC than Seed1,2,4 with right middle frontal gyrus, right superior frontal gyrus and left supplementary motor area separately.No significant positive or negative correlations between swallowing frequency and seed-based FC values were found.Conclusions: Saliva swallowing trail task with self-paced rhythm in sufficient time can activate swallowing-related brain regions effectively.The activation peaks in bilateral pericentral area are representative in swallowing process and could be new therapeutic targets for poststroke dysphagia instead of traditional route.