Association between the elements of a bivalent compound stimulus.

Evidence that an association forms between the elements of a bivalent compound stimulus during inhibitory training was provided in four experiments with rats in a conditioned suppression task. This association occurred both in a conditioned inhibition paradigm, which intermixed A+ and AX- trials (Experiments 1 and 2), and in an extinction-inhibition paradigm, which presented A+ and AX- training sequentially (Experiments 3 and 4). The within-compound association appeared to be bidirectional inasmuch as excitatory changes in the value of either component affected responding to the associated component. After inhibitory training in Experiments 1-3, pairings of the inhibitory stimulus (X) with shock increased suppression to the associated excitatory stimulus (A). In Experiment 4, additional pairings of the excitatory stimulus (A) with shock after inhibitory training increased suppression to the associated inhibitory stimulus (X). These studies add to a growing body of evidence on within-compound associations and encourage the development of a conceptual framework that provides an integrated description of within-compound and stimulus-reinforcer learning.