Participants

All procedures were approved by the Yale University Human Investigation Committee. All participants provided written informed consent and completed a demographic questionnaire and the Kaufman Brief Intelligence Test (46). All participants completed the Perceptual and Value-based Decision-Making task (PVDM, detailed below) and were compensated for their time.

A priori power analysis indicated that, given anticipated large effect sizes [Cohen's f > 0.4 (8)], to detect differences between 4 groups using ANCOVA while controlling for age and IQ with p < 0.05 and power equal to 0.8, we needed a total sample of N > 52 (47). We used HDDM to further improve the power of planned analyses (10).

Twenty-nine adults with OCD (17 females; age range = 18–62 years, mean = 31 ± 11 SD), unmedicated for at least 8 weeks, and thirty-two healthy adults (16 females; age range = 18–59 years, mean = 30 ± 11 SD) were recruited through the Yale OCD Research Clinic (ocd.yale.edu). Diagnoses were established by doctoral-level clinicians and confirmed using the Mini International Neuropsychiatric Interview 7.0.2 [MINI (48)]. Clinically significant OCD symptoms were defined as Y-BOCS ≥ 16. OCD was the primary clinical diagnosis in all twenty-nine individuals with OCD; fifteen of them also reported clinically significant comorbidities, which included panic disorder (7), depression (6), social phobia (4), agoraphobia (3), PTSD (2), and GAD (2). None of our study participants meet criteria for comorbid impulse control disorder. Severity of obsessions and compulsions was assessed using the Yale-Brown Obsessive-Compulsive Scale [Y-BOCS (49, 50)] and severity of depression using Beck Depression Inventory – II scale [BDI - II (51)]. OCD symptoms were also assessed dimensionally, using Obsessive-Compulsive Inventory revised [OCI-R, (52)], Dimensional Obsessive-Compulsive Scale [DOCS, (53)], and the Obsessive-Compulsive Trait Core Dimensions Questionnaire [OC-TCDQ, (54)]. These assessments were administered within 1 week of behavioral testing. Exclusion criteria included IQ <70, current severe major depression (BDI-II ≥ 29), a primary psychotic disorder, autism, moderate or severe substance use disorder within the past 6 months, and poor visual acuity (after correction).