Date of Award


Document Type


Degree Name

Master of Arts (MA)



First Advisor

Mark E. Bouton


Instrumental behavior often consists of sequences of responses, or chains, that lead to a primary reinforcing outcome. These responses often differ in terms of both topography and the discriminative stimuli that set the occasion for them. Previous studies have focused on two response chains. They have shown that extinction of R1 weakens the associated R2, and conversely that extinction of R2 also weakens R1. To expand what little we know about discriminated instrumental chains, as well as the associative structure that underlies them, in the present experiments we test the effects of separately extinguishing individual responses on other target responses within an S1-R1-S2-R2-S3-R3 chain. In Experiment 1, extinction of R2, but not R3, weakened R1. In Experiment 2, extinction of both R1 and R3 weakened R2. Finally, in Experiment 3, Extinction of R2 weakened R3 more than did extinction of R1. The results support the role of adjacency in discriminated chains, with importance being given to the immediately-preceding and following responses in supporting a target response. The results do not support the role of a psychological representation of the chain as a whole or a special role of the first response, which “launches” the chain, or the last response, which leads most directly to the primary reinforcer.



Number of Pages

48 p.

Included in

Psychology Commons