Project abstract Animals must acquire and integrate information over time in order to make decisions. In addition, as the environment changes, animals must use new information to update previous models of the world and revise their decision making process. We observe such decision making processes in mice by challenging them to use changing and probabilistic environmental information to choose a motor action to achieve water rewards. These tasks engage the striatum and evoke dynamic dopamine signaling which is thought to be crucial to the decision making process. Here we will use modern methods of analysis of motor action with simultaneous observation of bilateral activity in the dorsal and ventral striatum to understand how features of behavior, the environment, and reward history are encoded in the striatum during dynamic decision making. Our predictions highlight the potential importance of hemispheric asymmetry in striatal dopamine, SPN and PKA activity in action selection, motor behavior and stochasticity of choice. We will further test these predictions using use time locked perturbations of activity to understand the causal relationship of these signals to ongoing and future behavior.