This textbook is an introduction to systems and computational neuroscience with a special focus on cognition. It consists of three parts: Part I covers basic concepts and mathematical models of computational neuroscience, as well as cutting-edge topics. Part II is dedicated to building blocks of cognition: working memory (how our brain maintains and manipulates information online in the absence of any external input), decision making (how a choice is selected among multiple options under uncertainty and risk) and behavioral flexibility (how we direct our attention and control our actions). In Part III frontier research is discussed: models of large-scale multiregional brain systems, computational psychiatry, interface with Artificial Intelligence. The author emphasizes the viewpoint of neural circuits as dynamical systems, and cross-level (from genes and cell types to collective neural populations to behavior) mechanistic understanding of the brain and the mind. Taken together, a reader is offered the opportunity to become well versed in this highly cross-disciplinary field of the 21st century. Key Features: Rooted in the most recent advances in experimental studies of basic cognitive functions Introduces neurobiological and mathematical concepts so that the book is self-contained Heavily illustrated with high-quality figures that help to illuminate neurobiological concepts, present experimental findings, and explain mathematical models Concludes with a list of core cognitive behavior tasks, ten take-home messages, and three open questions for future research Computer model codes are available via GitHub for hands-on practice.