Effects of stimulus-response correspondence and verbal expectancy on choice reaction time.

The effects of S-R correspondence, verbal prediction, and stimulus discriminability were examined in a discrete, two-choice reaction-time task. Correctness of prediction and S-R correspondence were significant main effects. In addition, responses were significantly faster for correct predictions on noncorresponding trials than for incorrect predictions on corresponding trials. This latter finding indicates that an expectancy mechanism can partially offset the negative effect of spatial S-R noncorrespondence on absolute magnitude of choice reaction time.