Conditioning, Operant 22 article 16 Animals 14 animal experiment 14 priority journal 14 controlled study 12 nonhuman 12 Male 10 learning 10 male 10 Animal 8 Behavior, Animal 8 Choice Behavior 8 instrumental conditioning 8 Dopamine 6 Memory 6 Mice, Knockout 6 Reward 6 Support, Non-U.S. Gov't 6 animal 6 decision making 6 feeding behavior 6 physiology 6 Analysis of Variance 4 Animalia 4 Bufo arenarum 4 Cocaine 4 Decision-making 4 Dopamine Uptake Inhibitors 4 Extinction (Psychology) 4