The role of response directedness in discriminative and conditional stimulus control

Abstract

Six pigeons were trained to press a treadle for variable-interval reinforcement when a blue light was present on the response key; a red light signaled extinction. Subsequently the birds were trained on the reversal of this discrimination. During initial training the houselight was off in the operant chamber; during reversal training it was on. The subjects learned the discrimination problems, although they performed substantially more poorly than they do when the key- peck response is used. Wavelength generalization testing in extinction with the two houselight conditions alternating in blocks of trials revealed that the houselight cues had gained conditional control over discriminative responding; the gradients peaked at (or near) the appropriate S+ values in each context. Thus the directedness of the response affects discriminative stimulus control but not conditional stimulus control.