Abstract
Two experiments assessed whether similarity between the two elements of a compound would influence the degree of mediated extinction versus recovery from overshadowing in human causal judgements. In both Experiments 1 and 2, we assessed the influence of extinguishing one element of a two-element compound on judgements about the other element. In Experiment 1 we manipulated the physical similarity of the two elements of the compound; in Experiment 2, we used equivalence and distinctiveness pretraining in order to vary their functional similarity. We found that these procedures influenced mediated extinction and recovery from overshadowing as a function of both physical and acquired similarity and distinctiveness, respectively. The implications of these results for previously reported differences between humans and nonprimate animals are discussed.
This research was supported by Grant 56446 from the National Institute of Mental Health (NIMH) to B.W.B.
Notes
1It should be noted that Dickinson and Burke's Citation(1996) model would be able to predict mediated extinction and conditioning effects when the compound elements share a large number of physical features, as in Experiment 1, since those shared features will be actually present and therefore active in the A1 state when either of the two compound elements is presented. However, other factors relevant to our results (e.g., spatial proximity of compound elements and equivalence pretraining) clearly fall outside the scope of this model.