Speeded multielement decision-making as diffusion in a hypersphere: Theory and application to double-target detection

Abstract

We generalize the circular 2D diffusion model of Smith (Psychological Review, 123, 425–451: 2016) to provide a new model of speeded decision-making in multielement visual displays. We model decision-making in tasks with multielement displays as evidence accumulation by a vector-valued diffusion process in a hypersphere, whose radius represents the decision criterion for the task. We show that the methods used to derive response time and accuracy predictions for the 2D model can be applied, with only minor changes, to predict performance in higher-dimensional spaces as well. We apply the model to the double-target deficit paradigm of Duncan (Psychological Review, 87, 272–300: 1980) in which p..