The purpose of this study is to learn more about the brain circuits involved with effortful
control in healthy adult participants. Study participants will be given either
methylphenidate (also known as 'Ritalin')which is an FDA approved, most widely-used
medication given to those diagnosed with Attention Deficit Hyperactivity Disorder (ADHD)or a
placebo, which is a sugar pill. Each participant will also perform some computer tasks that
have been shown in previous studies to require effortful control while undergoing an fMRI
(functional Magnetic Resonance Imaging) which takes a special kind of picture of the brain.
Our goal is to learn more about the brain mechanisms by which methylphenidate improves
effortful control.