RecruitingDevice studyADHD PreSMA Response Inhibition TherapyADHD children have abnormal inhibitory control, meaning they have trouble stopping themselves from doing something they should not do. This ability to control involves an area in the brain called the pre-supplementary motor area (pre-SMA). Scientists have previously shown that the pre-SMA is abnormal in ADHD patients. In this study, we will use Transcranial Magnetic Stimulation (TMS) to stimulate the pre-SMA and determine the effects on measures that are related to inhibitory control.