, Volume 35, Issue 2, pp 137-143

The effects of stimulus sequence and probability on perceptual processing


Two experiments that tested the hypothesis that the effect of stimulus presentation probability on perceptual processing is a function of the preceding stimulus sequence are reported. Replicating previous findings, the magnitude of the probability effect was affected by stimulus quality. The interaction was unchanged when sequential effects were eliminated from the data. Stimulus quality and sequence displayed an additive relationship. These results suggest that the probability effect on perceptual processing is not an indirect result of sequential effects. Together with the results of Miller and Anbar (1981), they suggest that practice gradually acts to facilitate the perceptual processing of highly probable stimuli.

This research is based on a thesis submitted by the first author in partial fulfillment of the requirements for the Master of Science degree at the University of Massachusetts at Amherst. Preparation of this report was supported in part by National Science Foundation Grant SED-8113323 to the second author.