The Jamming Avoidance Response (JAR) of weakly electric fish allows them to distinguish biologically relevant electrosensory stimuli from interference due to the discharges of other fish. To correctly execute this behavior, they must interpret relationships between phase and amplitude modulations of their electric organ discharge field. This project will be an anatomical and physiological study of the electrosensory system in Sternopygus, an electric fish that does not exhibit a JAR. Characterizing in Sternopygus the areas associated with the JAR in other electric fish should provide clues about the evolution of this behavior, as well as brain structures that may have been preadaptations for its evolution. The long-term goals of this project are to gain insight into how nervous systems process sensory information, particularly the temporal components of this information. This knowledge can increase our understanding of temporal information processing in the human nervous system (e.g., speech perception).