The time course of perceptual choice: The leaky, competing accumulator model

The time course of perceptual choice is discussed in a model of gradual, le aky, stochastic. and competitive information accumulation in nonlinear deci sion units. Special cases of the model match a classical diffusion process, but leakage and competition work together to address several challenges to existing diffusion, random walk, and accumulator models. The model account s for data from choice tasks using both time-controlled (e.g., response sig nal) and standard reaction time paradigms and its adequacy compares favorab ly with other approaches. A new paradigm that controls the time of arrival of information supporting different choice alternatives provides further su pport. The model captures choice behavior regardless of the number of alter natives, accounting for the log-linear relation between reaction time and n umber of alternatives (Hick's law) and explains a complex pattern of visual and contextual priming in visual word identification.