Effect of separate presentation of the elements on within-compound learning in autoshaping

Five experiments used an autoshaping procedure with pigeon subjects to explore the consequences of separate-element presentation for within-compound associations. When a keylight compound had initially been reinforced, separate presentation of one element reduced responding to the other. This was true whether that separate-element presentation was itself reinforced or nonreinforced. That suggests that the detrimental effect of separate-element presentation results from an effect on the within-compound association, rather than one on the association of either element with the US. When the compound had initially been nonreinforced, a moderate level of reinforcement of one element resulted in responding to the other element. However, more extensive reinforcement reduced that responding. Moreover, an attempt to reverse the adverse consequences of extensive separate-element presentation by further exposure to the compound was not successful. These results comment on the associative mechanisms underlying performance in sensory preconditioning and related paradigms.