Stability of emergent simple discriminations in young children.

This study compared two procedures for establishing and reversing stimulus control transfer across simple discriminations in children. One procedure, stimulus contiguity, started with training of a color discrimination task, red omega (S+) vs yellow omega (S-). This task was followed by two nonreinforced tests, one with colored forms, red lambda and yellow pi; and one with black forms, lambda and pi. Children who selected the lambda on both tests received a reversal task. Two types of reversals were used: one in which the contingencies for red and yellow were reversed (Reversal 1) and one in which the forms were presented with opposite colors, yellow lambda and red pi (Reversal 2). The second procedure, match-to-sample training, was the same except that the colors and forms were conditionally related to one another. The results showed that (a) both procedures were more effective in establishing than in reversing stimulus control transfer, (b) Stimulus Contiguity was more effective than match-to-sample training, and (c) both procedures were more effective in changing the form discrimination with Reversal 1 than with Reversal 2.