Four experiments used between- and within-subject designs to examine appetitive-aversive interactions in rats. Experiments 1 and 2 examined the effect of an excitatory appetitive conditioned stimulus (CS) on acquisition and extinction of conditioned fear. In Experiment 1, a CS shocked in a compound with an appetitive excitor (i.e., a stimulus…

Summation is the usual result in composition procedures with excitatory stimuli. However, summation is difficult to obtain in autoshaping with pigeons. The problems with this preparation have been related to the stimuli used: combinations of intramodal conditioned stimuli (CSs). During the perceptual processing of this type of stimuli, some mutual…

Aversive events can trigger relapse of extinguished fear memories, presenting a major challenge to the long-term efficacy of therapeutic interventions. Here, we examined factors regulating the relapse of extinguished fear after exposure of rats to a dangerous context. Rats received unsignaled shock in a distinct context ("dangerous"…