Prior probabilities and representational momentum

Abstract

In many previous experiments on representational momentum (in which memory for the final location of a moving target is displaced in the direction of target motion), participants judged whether a probe presented after a target vanished was at the same location where that target vanished or at a different location. The experiments reported here manipulated the actual or expected prior probability a same response to such a probe would be correct. In Experiment 1, a same response was correct on 10%, 30%, 50%, 70%, or 90% of the trials, but observers were not instructed regarding these probabilities. In Experiment 2, a same response was correct on 11% of the trials, but different groups of participants were instructed that a same response would be correct on 10%, 30%, 50%, 70%, or 90% of the trials. Probabilities of a same response to different probe positions, weighted mean estimates of representational momentum, hit rates and false alarm rates, and d′ and ß are reported. Representational momentum occurred in all conditions but was not influenced by actual or expected prior probability a same response would be correct. The data suggest representational momentum does not result from changes in sensitivity, and a distinction between performance bias and competence bias is introduced.