Differential effects of two ways of devaluing the unconditioned stimulus after Pavlovian appetitive conditioning

Three experiments with 56 male Sprague-Dawley rats investigated the effects of 2 methods of devaluing a food UCS after pairings of an auditory CS with that UCS. Exp I found no effect of postconditioning pairings of the food UCS with lithium chloride (LiCl) on general activity to a tone CS, even though those pairings substantially reduced food consumption. Exps II and III compared the effects on conditioned responding of postconditioning pairings of food with LiCl and with high-speed rotation. In these experiments the general activity measure was supplemented by a detailed visual analysis of Ss' behavior. Exp II found that food-rotation pairings had larger effects than food-LiCl pairings on general activity responding and on 2 detailed behavioral measures but that food-LiCl pairings had larger effects on food consumption and on one behavioral measure. Exp III replicated the findings of Exp II and found that the ability of the CS to serve as a reinforcer for 2nd-order conditioning after UCS devaluation was reduced more by food-LiCl pairings. (12 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).