ASPECTS OF THE REINFORCER LEARNED IN 2ND-ORDER PAVLOVIAN CONDITIONING

Four experiments used an autoshaping procedure in 66 female White Carneaux pigeons to explore learning about the reinforcer in a 2nd-order conditioning paradigm. Exp I conditioned 2 visual 2nd-order stimuli (S2), using as reinforcers 2 visual 1st-order stimuli (S1), each of which had been paired with food. Ss for which the S2 stimuli were each consistently paired with one particular S1 developed 2nd-order responding more rapidly than did Ss for which the identity of S1 varied in trials. Moreover, following consistent pairings, extinction of an S1 had a depressive effect on 2nd-order responding that was peculiar to the S2 with which it had been paired. Results suggest that the organism identified a particular S1 as the reinforcer for each S2. Exps III and IV examined that identification. A compound S1, itself composed of 2 separable elements, was used to reinforce an S2. Extinction of either element of S1 led to a depression in the responding to S2, indicating that both elements were involved in the 2nd-order conditioning. Moreover, the use of several complex discriminations, which produced different behavior to S1 and its elements, suggests that the organism had associated the S2 with the compound S1 rather than with its separate elements. However, even complete extinction of the response to S1 left some residual behavior to S2, indicating that a portion of the 2nd-order conditioning is independent of the current state of the reinforcer. These results demonstrate that in some situations the organism associates a CS with a rich representation of the reinforcer. (16 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.