Avoidance of hot air blast in Rattus norvegicus.

The hegemonic use of electric shock as an aversive stimulus limits what is known about the generality of avoidance behavior and related phenomena. The purpose of this study was to investigate the effects of using the hot air blast (HAB) instead of electric shock as an aversive stimulus in avoidance conditioning. Four male Wistar rats were exposed to a discrete-trial procedure. In the first phase, the emission of a lever-press response during a trial was positively reinforced. In the second phase, the same contingency was employed, but an escapable HAB was presented at the end of a trial when no response was emitted. In the third phase, positive reinforcement was suspended and a discrete-trial avoidance procedure was employed. In the fourth phase, HAB presentation was completely suspended. As a result, all subjects learned the avoidance response and showed a marked reduction in its frequency during HAB suspension. These results offer evidence indicating that avoidance behavior is controlled by the HAB, thereby advancing the understanding of the generality of this stimulus as being aversive.