Fig. 1.

Graphical illustration of the drift–diffusion mode. Note. The decision process begins at the starting point z. Over the time more and more information will be accumulated until one of both thresholds is reached. The drift parameter v represents the strength and direction of the evidence accumulation process (represented by the black arrow). The parameter a describes the distance between both thresholds. The figure does not display the non-decision time t₀. Figure with permission from Frischkorn and Schubert (2018), licensed under CC BY