A Bayesian approach can contribute to an understanding of the brain onmultiple levels, by giving normative predictions about how an ideal sensory systemshould combine prior knowledge and observation, by providing mechanisticinterpretation of the dynamic functioning of the brain circuit, and by suggestingoptimal ways of deciphering experimental data. Bayesian Brain brings togethercontributions from both experimental and theoretical neuroscientists that examinethe brain mechanisms of perception, decision making, and motor control according tothe concepts of Bayesian estimation.After an overview of the mathematical concepts, including Bayes' theorem, that are basic to understanding the approaches discussed, contributors discuss how Bayesian concepts can be used for interpretation of suchneurobiological data as neural spikes and functional brain imaging. Next, contributors examine the modeling of sensory processing, including the neural codingof information about the outside world. Finally, contributors explore dynamicprocesses for proper behaviors, including the mathematics of the speed and accuracyof perceptual decisions and neural models of belief propagation.