The broad goals of the proposed effort are to increase the understanding of the contributions of evaluative processes to behavior. Evaluative dispositions, as manifested by approach/avoidance tendencies or appetitive/aversive reactions, are ubiquitous in behavioral contexts, and can range from reflexive responses to simple stimuli, to generalized attitudinal dispositions to broad classes of stimuli. Of particular interest are the multiple levels of evaluative processes that may be operative in a given behavioral context, and the potential interactions among these processes. These issues will be addressed in chimpanzees, through studies of a potent TIE that appears to arise from competing evaluative dispositions to food arrays. The proposed studies will examine the social, perceptual, and incentive determinants of this task interference. The proposed effort will also test a conceptual model of the levels of evaluative processing, and will further develop this model. The loner- term goal is to elucidate the antecedents, consequents, and neurobiological mechanisms of evaluative processes. Given the unique phylogenetic status of chimpanzees, this species may be optimal for bridging the gap between the human and animal literatures on evaluative processes.
