An opponent-process interpretation of postshock bursts in appetitive responding

While eight food-deprived rats pressed a lever for food during daily 1-h sessions, four CS-Shock₂ trials were presented. Trials were preceded by either a Shock₁ of .25, .50, .75 mA or no Shock₁. It was found that the rate of appetitive responding during the CS was greater on Shock₁-CS-Shock₂ trials relative to CS-Shock₂ trials. The data indicate that the phenomenon of postshock bursts in responding can occur in the absence of a signal for safety after shock. The results conform to the predictions of the opponent-process theory of motivation.