The studies in this proposal are designed to explore the associative, circuit and neural basis of conditioned reinforcement (CRf). CRf is the process by which a cue gains significance through pairing with a primary reinforcer, i.e. food or drugs to support behavior in the absence of the primary reinforcer. CRf may be important to normal and maladaptive human behavior, such as drug addiction, where cues present in a drug taking environment can later support drug-seeking and even relapse. These cues may become associated with the outcome itself (primary reinforcer, i.e. drug) and/or the general affect (a feeling or an emotional tone) associated with that outcome. Using learning tasks we will create cues with more selective or biased representations to tease apart the specific representations underlying conditioned reinforcers. Furthermore, using lesion and behavioral recording techniques, we will identify how critical learning areas, such as basolateral amygdala and orbitofrontal cortex, mediate CRf supported by different types of associative learning. The design of this proposal will lead to a greater understanding of the associative and neural basis of normal and pathological human behavior. Conditioned reinforcement is widely studied in the drug addiction field. Cues associated with drug-taking, after periods of withdraw! are able to evoke or support drug-craving, seeking and taking behavior. We hope to further elucidate, in this proposal, what properties underlie such contextual cues, acting conditioned reinforcers, which may lead to destructive behavior.