Revisiting verbal recognition memory in obsessive-compulsive disorder: A computational approach

Deficits in primary recognition memory and confidence have previously been tested as potential contributors to excessive checking behavior in obsessive-compulsive disorder. Studies have tested both recognition for actions and, hypothesizing that recognition may be disrupted more generally across content domains, verbal recognition memory. However, studies of verbal recognition memory have yielded mixed results. We revisited this work with the benefit of hindsight, running two new experiments with larger samples, the manipulation of recognition difficulty, and a computational model-based approach to data analysis. In both datasets, we found that discriminability, defined as the difference in drift rate for old versus new stimuli in the drift-diffusion model, was reduced as a function of subclinical OCD symptoms in the general population. Paralleling work on drift rate deficits in perceptual decision making in OCD, these reductions were larger for easier recognition decisions. We also asked participants about their confidence in each recognition decision and parcellated confidence into bias, or the difference in overall confidence, and sensitivity, which represents the ability to appropriately map confidence to objective accuracy. We found no consistent evidence of a relationship between OCD symptoms and either quantity.