Wavelength Generalization after Discrimination Learning with and without Errors

Pigeons were trained to discriminate between 580 mk (S+) and 540 m� (S-) by procedures which resulted in either a large amount of responding to S-or in little or no responding to S-. A shift in the peak of a postdiscrimination generalization gradient, away from S-, was obtained only if the discrimination was learned with a large amount of responding to S-.