The limitations of current clinical taxonomies have hindered progress in delineating important neurocognitive correlates of mental health. For instance, dysfunctions in goal-directed control and metacognition are implicated in obsessive-compulsive disorder (OCD), but these effects are either inconsistent and/or unspecific to OCD. In this talk, I will present a series of behavioral and EEG studies which utilize a dimensional approach that appreciates the continuum of mental illness to characterize neurocognitive correlates relating to a specific, transdiagnostic clinical dimension of compulsivity. These studies aim to reconcile metacognitive findings in compulsivity with a related literature on goal-directed control, suggesting that goal-directed deficits of compulsivity may be attributed to problems in curating the mental model. Moreover, I will underscore the advantages of the dimensional approach across these studies, such as enabling specificity of our observed effects as well as revealing effects that may be obscured in case-control observations, highlighting its potential as a path towards precision medicine in psychiatry.