Reversal and nonreversal shifts with verbal material

2 experiments were conducted to investigate the influence of mediating responses on reversal and nonreversal shifts with verbal materials containing 2 dimensions or representing 2 aspects of concreteness simultaneously. In Exp. I, the tasks involved form and color dimensions, with 2 and 4 stimulus cues being used. The 2 cue-group learned faster than the 4 cue-group in original and shift learning. Reversal shift was easier than nonreversal shift. In Exp. II, the tasks involved two aspects of concreteness (food and color), and 2 and 4 cues. Original learning was easy only when the food was relevant. Reversal shift was easier than nonreversal shift and in reversal shift no difference between the 2 and 4 cues was found, but in nonreversal shift some difference was found. The relevance of these findings to mediational S-R theory and response-switching theory was discussed.