How does light energy falling on the back of our eye get interpreted as a particular image of our friend or a painting or a leaf? How does a cockroach escape imminent predation by a toad? How does a slug remember that a recent poke wasn’t dangerous? How do we remember? A rigorous consideration of general principles of neural integration at the cellular, sensory, central, and motor levels of organization serves as the groundwork for an examination of such questions of integration. Then we apply those principles to particular systems in vertebrates and invertebrates. Students read appropriate primary literature and conduct their own research projects.