A fast procedure for studying conditional accuracy functions

Abstract

This paper describes a procedure for obtaining conditional accuracy functions(CAFs) from naive observers and a restricted number of trials. The method permits the experimenter to counter the subjects' tendency to favor accuracy in tasks in which stimulus discrimination is easy. Each time a block of 12 trials contains less than three errors, observers are instructed, by means of a speed-up signal, to respond faster. The subject is continuously informed about her/his effective reaction time. The data show that the desired speed-accuracy tradeoff was obtained within each of the 7 observers. The mean percent error was around 25%. © 1993 Psychonomic Society, Inc.