Imagine that you have just rung at a doorbell and no one has answered the door. Is there anybody home? How many times should you ring? One simple solution is just to ring several more times and wait. Yet, to save time and make sure that no one is home, you could also consider whether there is a light inside the house or whether there is a car parked in front. Although such situations are ubiquitous in our daily life, relatively little is known about how different decisions are implemented in the brain and how they flexibly inform behavior. This proposal directly aims to characterize decision variables both at the behavioral and neural levels to understand how the brain flexibly switches between them. We will combine sophisticated mice behaviors that accommodate multiple decision variables with innovative models of dynamical systems, and leverage the latest progress in electrophysiology and optogenetics to record and manipulate large ensembles of neurons simultaneously across multiple brain regions. This work will test the overarching hypothesis that the premotor cortex, thought to implement the intention to act, is a reservoir of decision variables that flexibly routes the employed decision variable to motor regions. Our highly multidisciplinary team, which consists of the researcher with productive records in systems neuroscience, the supervisor who is a specialist in cognitive neuropsychology, and the secondment supervisor who is a renowned theoretical neuroscientist, is well armed to successfully carry this project. Our results should deliver a new conceptual framework for understanding adaptive behaviors and their neural bases. This project will also provide a direct window into the neural mechanisms underlying individual variations in decision making and how actions may depart from a healthy behavior when erroneous or maladaptive strategies are used, of relevance for explaining diversity in human behavior and mental health.