Some new perspectives on conditioned hunger

Conducted 5 experiments with a total of 136 male Sprague-Dawley albino rats to determine whether the modality of the conditioned stimulus (CS) and the index used for conditioned drive are important in demonstrating the conditioning of hunger, using natural deprivation as the unconditioned stimulus (UCS). Exps I-III provide some support for the hypothesis that appetitive drives such as hunger and thirst are not conditionable because of slow onset. This suggests that the dependent measures used in past experiments may not be valid. Exps IV-V suggest that changes in the rate of barpressing on an operant extinction curve following probe CSs for hunger may be a more sensitive and valid index of conditioned appetitive drive. Results indicate a need for a re-examination of the basic difference between appetitive and aversive drives, which lies in the mode of their onset and control and which, given adaptive considerations, can account for their widely different conditionability. (41 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).