Our goal is to understand how the brain integrates sensory information and selects and executes appropriate actions. In particular, we aim to determine the organization and function of neural circuits underlying visually guided behaviors. We use the zebrafish as a model organism because it allows us to visualize and manipulate activity in neural circuits throughout a vertebrate brain. As early as one week post-fertilization, zebrafish display a rich repertoire of innate visual behaviors, following moving patterns, avoiding predators and tracking and capturing live prey. With no skull and transparent skin, the entire volume of the brain can be imaged non-invasively in one field of view, and many neurons are individually identifiable from fish to fish. Our approach has three main themes: 1) Quantitative analysis of behavior. 2) Whole brain imaging of neural activity dynamics in the behaving animal. 3) Perturbation of identified neurons to reveal their role in sensorimotor integration. In parallel, we are developing new genetic tools that allow more specific targeting and manipulation of identified cell types.