Failure of a peripheral muscle relaxant (suxomethonium bromide) to increase the efficacy of flooding (response prevention) in rats

Extinction of avoidance responding in rats: The noise-intensity parameter in noise-facilitation of flooding.

“…Recent demonstrations of sign-tracking in aversive conditioning (Leclerc & Reberg, 1980;Leclerc, 1985) can perhaps offer a more promising interpretation of the effects of noise during flooding. These studies show that, in the absence of any instrumental contingency, rats tend to avoid contact with stimuli which predict shock (e.g., the grid floor of our apparatus) and approach stimuli which signal the nonoccurrence of shock (possibly, the safety ledge).…”

“…Flooding (response prevention) generally facilitates avoidance extinction (see Baum, 1970, Baum, 1976 for reviews). However, under conditions where shock is intense during acquisition (e.g., 1.3 mA for the rat) and the duration of flooding is relatively short (e.g., 3 or 5 minutes total exposure time to the evocative stimulus), the efficacy of unassisted flooding in hastening subsequent avoidance extinction is limited and the procedure has little effect (Baum, 1969; Baum, Leclerc, & St. Laurent, 1973; Baum, Roy, & Leclerc, 1985; Leclerc, St. Laurent, & Baum, 1973). Under such circumstances, flooding efficacy can be enhanced by the continuous sounding of a loud buzzer during the flooding period (Baum & Gordon, 1970).…”