The Effect of Folic Acid Supplementation in the First Trimester of Pregnancy on Perinatal Outcomes: A Retrospective Cohort Study https://www.imrpress.com/journal/CEOG/51/9/10.31083/j.ceog5109202
fMRI scans of 151 participants showed that bilingual people had better connectivity between brain regions, especially if they learned their second language at a younger age. This effect was especially strong between the cerebellum and the left frontal cortex