An equivalence class is typically established when a subject is taught a set of interrelated conditional discriminations with physically unrelated stimuli and additional, untaught, conditional discriminations are then demonstrated. Interestingly, and perhaps counter-intuitively, the relations among the stimuli within such a class are not…

Generalization gradients have been investigated widely in animal conditioning experiments, but much less so in human predictive learning tasks. Here, we apply the experimental design of a recent study on conditioned fear generalization in humans (Lissek et al., 2008) to a predictive learning task, and examine the effects of a number of relevant…

The failure to discriminate between a pattern consisting of four orthogonal bars and the same pattern rotated by 45 degrees has been interpreted in the literature as evidence against pictorial representations in honeybees. This study determines whether prior training can facilitate the discrimination. In Experiment 1, one group of bumblebees was…