The study will enroll 70 children with ADHD, aged 6-12, who are participating in the main randomized controlled trial: 40 from the BrainpalTM intervention group and 30 from the control group; participants will undergo fMRI scan at Week 0 and 8 or Week 8 and 16. The study will recruit another 30 children aged 6-12 from the community as the healthy control group, who will undergo the same imaging procedure once. The scans will involve both functional and structural imaging.