Proceedings of the Annual Meeting of the Cognitive Science Society

ime-accuracy functions are obtained by measuring the accuracy of a subject's responses at various levels of stimulus presentation time. Unlike reaction time (RT) measurements, which convey information about the entire set of processes taking place between the onset of the stimulus and the production of a response, time-accuracy functions (TAFs) focus on a subset of those processes, namely stimulus-limited processes. Stimulus-limited processes are responsible for the extraction of the perceptual information that is necessary for the elaboration of a response. Post-stimulus processes take care of selecting and executing the response based on the information extracted by stimulus-limited processes. This paper presents a method of analysis that allows us to (a) extract estimates of the duration and variance of stimulus?limited processes from individual TAFs and (b) combine these estimates with RT data in order to induce the duration and variance of post-stimulus processes. The method is illustrated with data from a subitizing (speeded enumeration) task.