This textbook is an introduction to Systems and Theoretical/Computational Neuroscience, with a particular emphasis on cognition. It consists of three parts: Part I covers fundamental concepts and mathematical models in computational neuroscience, along with cutting-edge topics. Part II explores the building blocks of cognition, including working memory (how the brain maintains and manipulates information "online" without external input), decision making (how choices are made among multiple options under conditions of uncertainty and risk) and behavioral flexibility (how we direct attention and control actions). Part III is dedicated to frontier research, covering models of large-scale multi-regional brain systems, Computational Psychiatry and the interface with Artificial Intelligence. The author highlights the perspective of neural circuits as dynamical systems, and emphasizes a cross-level mechanistic understanding of the brain and mind, from genes and cell types to collective neural populations and behavior. Overall, this textbook provides an opportunity for readers to become well versed in this highly interdisciplinary field of the twenty-first 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 (https://github.com/xjwanglab/book) “In this textbook, Xiao-Jing Wang takes the reader on a remarkable journey from cellular and synaptic biophysics to memory, decision making, psychiatry and large-scale brain structure. His insights on how to apply theoretical methods to higher cognitive functions will be valuable to anyone thinking about thinking.” - Larry Abbott, William Bloor Professor of Theoretical Neuroscience, Columbia University, 2024 Brain Prize winner, co-author with Peter Dayan of “Theoretical Neuroscience”. “X-J Wang's book illuminates how in the past decades a new field has emerged from the theoretical modeling of a wide diversity of neural processes which has successfully contributed to our understanding of brain functions up to Cognition. The book progresses from the most elementary building blocks of the brain, neurons, synapses and their molecular components up to global executive functions and the new field of computational psychiatry. The immense knowledge recently acquired and beautifully presented in the book is a must for anybody concerned by the higher functions of the brain: a bible for the students, a grandiose panorama for the educated scientists.” - Jean-Pierre Changeux, Institute Pasteur, Paris; author of "Neuronal Man: the Biology of Mind" “This compelling book explains foundational concepts in theory and modeling in a way that marries rigor with intuition. It furnishes readers with powerful theory and modeling tools that are critically needed to tackle problems in modern neuroscience. Wang’s explanations of network dynamics, normalization and attractor models for cognition are certain to inspire experimentalists and theorists alike.” - Anne Churchland, Professor, UCLA “In 'Theoretical Neuroscience', Xiao-Xing Wang explains that while the brain is not a computer, all of its elements, from synapses to circuits, obey computational principles that underlie our cognitive functions. As a leader in the computational field, he gives an insider’s account of these principles at both a mathematical and conceptual level. This should be required reading for any student of modern neuroscience.” - Robert Desimone, Director of the McGovern Instute for Brain Rearch, Doris and Don Berkey Professor of Neuroscience, MIT “In the 20th century, Molecular Biology decoded the intricate mechanisms of DNA and RNA, the “logic of life” celebrated by Nobel prize François Jacob. Understanding the logic of neural circuits of cognition is an equivalent goal for 21st century in Neuroscience.This important book represents a fundamental step forward: it provides a synthesis of elemental circuit building blocks of core cognitive functions, how their operation can be mathematically modeled, and how their composition may account for a variety of cognitive processes and behavioral tasks” - Stanislas Dehaene, Chair of Experimental Cognitive Psychology, Collège de France, Paris. 2014 Brain Prize winner “Understanding the brain needs an appreciation of its components and activity over a wide range of spatial and temporal scales: from synapses to whole brain circuits, from rapid sensory and motor responses to lifetime memory. In this book Xiao-Jing Wang beautifully shows how theoretical and mathematical thinking can pro