Brain imaging reveals that obsessive-compulsive disorder involves disrupted activity patterns in the rostrolateral prefrontal cortex during sequential cognitive tasks. Researchers measured "ramping" activity—the progressive increase in neural firing as people work through ordered sequences of actions—and found altered patterns in OCD patients compared to healthy controls. The prefrontal cortex normally shows this ramping pattern when tracking progress through abstract sequences, like following a recipe or completing morning routines. This finding illuminates a neurological basis for the repetitive, rule-bound behaviors characteristic of OCD. The research fills a critical gap in understanding how hierarchical cognitive control operates in psychiatric conditions. Previous work established that task-switching abilities are impaired in OCD, but the sequential context of these deficits remained unclear. By examining both abstract sequence monitoring and task-switching simultaneously, the study reveals how disrupted prefrontal dynamics may contribute to compulsive ritualistic behaviors. The implications extend beyond OCD to other conditions involving cognitive inflexibility. However, the behavioral differences between OCD patients and controls were only partial, suggesting that compensatory mechanisms or medication effects may mask some neural dysfunction. Future research should examine whether these ramping deficits predict treatment response or symptom severity.