FEAR-POTENTIATED STARTLE USING 3 CONDITIONED-STIMULUS MODALITIES

The capacities of three different conditioned stimulus modalities (lig ht, noise, and airflow produced by a fan) to produce fear-potentiated startle were evaluated. Previous experiments have shown that following either light-shock or noise-shock pairings, both the Light and noise conditioned stimuli acquire the ability to potentiate the acoustically elicited startle response in rats (the so-called fear-potentiated sta rtle effect). In Experiment 1, the ability of airflow produced by a fa n to act as a conditioned stimulus was investigated. Rats were given e ither paired or unpaired fan-shock training followed by a test for fea r-potentiated startle. The fan conditioned stimulus potentiated startl e only in the group given explicit fan-shock pairings. In Experiment 2 , we evaluated the discriminability of the three conditioned stimulus modalities. Rats were given light, noise, or fan-shock pairings and we re subsequently tested for fear-potentiated startle with the trained c onditioned stimulus as well as the two remaining novel conditioned sti muli. Only the trained conditioned stimulus potentiated startle. These results show that fear-potentiated startle can be produced with three discriminable conditioned stimulus modalities, allowing the future us e of fear-potentiated startle in the investigation of higher order con ditioning phenomena.