Obsessive-compulsive disorder (OCD) is a neurological disorder characterized by repeated behaviors such as cleaning and checking despite clear objective evidence of cleanliness, orderliness, and correctness. Although the disease is often mischaracterized as a disorder of ‘fussiness,’ the disorder actually stems from difficulty in processing uncertainty. However, the neural underpinnings of that aberrant processing remains unknown. Now, a new study uses brain imaging to get a closer look at the underpinnings of uncertainty processing in OCD.