The extraction of cooccurrences between two events, A and B, is a central learning mechanism shared by all species capable of associative learning. Formally, the cooccurrence of events A and B appearing in a sequence is measured by the transitional probability (TP) between these events, and it corresponds to the probability of the second stimulus…

Four experiments examined the effects of a dangerous context and a systemic epinephrine injection on sensory preconditioning in rats. In each experiment, rats were exposed to presentations of a tone and light in stage 1, light-shock pairings in stage 2, and test presentations of the tone alone and light alone in stage 3. Presentations of the tone…

The present study evaluates the updating of long-term memory for duration. After learning a temporal discrimination associating one lever with a standard duration (4 sec) and another lever with both a shorter (1-sec) and a longer (16-sec) duration, rats underwent a single session for learning a new standard duration. The temporal generalization…

In conditioned odor aversion (COA), the association of a tasteless odorized solution (the conditioned stimulus [CS]) with an intraperitoneal injection of LiCl (the unconditioned stimulus [US]), which produces visceral malaise, results in its future avoidance. The strength of this associative memory is mainly dependent on two parameters, that is,…