STIMULUS PROBABILITY AS A DETERMINANT OF DISCRETE CHOICE REACTION TIME

Tested the hypothesis that stimulus probability is a critical determinant of choice RT only when stimulus alternatives are represented within Ss positive set, i.e., the stored alternatives against which stimulus input is compared prior to response selection. The likelihood that a particular pair of unequally probable stimuli would appear in S's positive set was varied across conditions by manipulating the pattern of stimulus-response correspondences. Mean RTs, error frequencies, and subjective reports supported the hypothesis. (15 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.