Bayesian decision theory is a way to understand how people make decisions when they are uncertain. In recent years, scientists have been using this theory to explain how our minds work. They have found that Bayesian models can help us understand how we see things and move our bodies. Some key points discussed include why Bayesian decision theory is important, how well it explains cognitive processes, the challenges of using it in practice, different ways to interpret the models, and how our brains might use Bayesian reasoning.