Memories often require the pulling together of different elements of information. "Associative learning" is the process by which humans and other animals learn to connect, or associate, different elements, events, or concepts. A fundamental form of this process is classical conditioning. Rats will learn that one stimulus, such as a tone or a light, is associated with the occurrence of another stimulus, such as a food pellet or a mild footshock; the tone or light will come to evoke behavior, such as a mild fear, provided the subject has learned to associate that stimulus with footshock and then remembers the stimulus-footshock association. This project will investigate memory and behavior when stimuli are associated with conflicting events or stimuli (e.g., shock and food, or food and no food). Previous research has shown that memory and behavior in this situation is strongly determined by the current "context," stimuli that are present in the background, which can select between competing associations. Behavior evoked by stimuli associated with multiple events can also change as the memories age over time. The project will investigate how time and context influence memory and performance, and also how the effects of time and context might interact. By studying the effects of time and context on behavior over a range of related situations, the research will provide insight into how ambiguous information is stored, retrieved, and then expressed in behavior and emotional performance. The research will have its primary impact on theories of learning, memory, and acquired motivation. It will also be relevant to research on the neurobiology of learning and memory, which has recently begun to identify biological processes in cells of the brain that may correspond to the learning and memory processes investigated here. The results will also have implications for cognitive-behavioral therapies of human behavior disorders (e.g., drug dependence and anxiety), which often introduce new learning designed to conflict with cognition and behavior based on previous learning.
