Applying a drift diffusion model to test the effect of oxytocin on attentional biases in body dysmorphic disorder

Individuals with body dysmorphic disorder (BDD) display selective attentional biases to threat. Oxytocin is an endogenous neuropeptide proposed to modulate attentional salience in social contexts. We conducted a sec-ondary analysis applying drift diffusion modeling (DDM) to test whether individuals with BDD would display an attentional bias to threat, and whether oxytocin would modulate this bias. Eighteen participants with BDD and 15 healthy controls received an oxytocin or placebo nasal spray during two study visits, in randomized order, and completed a modified spatial cueing paradigm. DDM successfully parsed distinct task components demonstrating a selective attentional bias to disgust versus neutral faces in BDD compared to controls in the placebo condition, and a main effect of oxytocin on exacerbating this bias across participants. There were no effects using mean reaction time measures. DDM may reveal insights about attentional biases by utilizing trial-wise information. Oxytocin may exacerbate attentional biases to threat in BDD.General scientific summary: Drift diffusion modeling successfully parsed distinct components of a modified spatial cueing task that assessed attentional biases in those with body dysmorphic disorder (BDD) and healthy controls that were missed in conventional analyses using mean reaction time measures. Individuals with BDD displayed an attentional preference for disgust versus neutral faces in the placebo condition, and oxytocin exacerbated this attentional bias.