Mesocorticostriatal dopamine projections are crucial for value learning, motivational control, and cognitive functions. However, while dopamine’s role in value learning as reward-prediction-error (RPE) has been much understood, precise roles in motivational control and cognitive functions remain more elusive. Computationally, this corresponds to that while the operation of mesostriatal dopamine could be minimally described by simple reinforcement learning (RL) models with one-dimensional reward/RPE and fixed state representation, how reward-specific motivational control can be achieved through heterogeneous dopamine responses, and how sophisticated cortical state representation can be formed through mesocortical dopamine, cannot be captured by such simple models.