Influence of visual conditioned stimulus characteristics on the form of Pavlovian appetitive conditioned responding in rats

Conducted 3 experiments with a total of 108 male Sprague-Dawley rats. In Exp I, localized CSs evoked behaviors mostly directed toward the CS source, and more diffuse CSs evoked behaviors mostly directed toward the delivery site of the food UCS. In Exp II, localized CSs nearer the UCS delivery site evoked more CS-directed but less UCS site-directed behaviors than localized CSs farther from the UCS delivery site. In Exp III, the extent to which Ss contacted CS sources depended on variation in several CS features casually described as affecting the feasibility of contact with those CSs. In all 3 experiments, some differences in behavior evoked by the various CSs were noted prior to conditioning; these differences were enhanced by conditioning and further magnified by discrimination training. These results are related to a hypothesis in which orienting responses play an important role in determining the character of Pavlovian conditioned responding. (20 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).