Diffusion and Random Walk Processes

Abstract

Diffusion and random walk processes comprise one of the main classes of sequential-sampling models for decision making and choice response time in psychology. The models assume that decisions are made by accumulating samples of noisy evidence to a response criterion, either in continuous or in discrete time. The models successfully predict the main features of performance in speeded decision tasks: accuracy, the ordering of mean response times for correct responses and errors, the shapes of response time distributions, and the effect of instructions. Neural correlates of the evidence accumulation process have been identified in studies of the brain regions involved in decision making.