Understanding how we learn the relationships between events in the world, and how we learn to respond appropriately to those events has been an important focus of research in psychology and the cognitive sciences for many years. While many different theories have been proposed, two broad classes of accounts have been particularly popular. Findings from studies of animal conditioning and tasks requiring humans learners to make very fast responses have led to proposals that learning in these tasks is based on a process of gradual adjustments to pathways linking representations of cue events to representations of their outcomes and appropriate responses to those outcomes. However, many of the same findings can also be explained as a process of making explicit inferences about the likely causal relationships between events. Findings from human contingency learning tasks have been argued to support the idea that learners in these tasks rely on an inference-based reasoning process. This has led some to doubt that both types of processes necessarily exist. The experiments presented in this thesis set out to look for evidence that both processes exist, and that they are preferentially involved in different kinds of learning situations. In the presented experiments, participants saw displays containing single or paired objects and learned which displays were usually followed by the appearance of a dot shortly afterward. Some participants predicted whether the dot would appear and then saw the outcome, while others were required to respond very quickly if the dot appeared shortly after the objects. For prediction participants, instructions that guided them to infer which objects had the power to cause the dot outcome determined whether contingencies associated with one object affected predictions about its pair mate. For fast-paced responding participants, contingencies associated with one object affected responses to the pair-mate, even when more neutral instructions were provided. These results challenge single-mechanism accounts and support the proposal that the mechanisms underlying performance in the two tasks are distinct. The remainder of the thesis focuses on the development of computational models of the different kinds of processes thought to underlie responding in these tasks.