We routinely face decisions requiring evaluation and choice of different actions may or may not yield different types of rewards. These situations trigger competitive decision biases that reflect interplay between different prefrontal cortical, amygdalar, striatal and habenular nodes within the brain’s dopamine system, which plays a critical role in action selection and reward processing. This lecture discusses some of the interactions between these circuits that shape decision biases and underlie conflicting urges when evaluating options that vary in terms of potential risks and rewards. Subcortical circuitry linking the amygdala and the ventral striatum appears to promote a more visceral bias towards larger, uncertain rewards, whereas prefrontal regions serve to temper these urges when riskier options become less profitable via top-down control over the amygdala. Dopamine transmission within these regions also makes dissociable, yet complementary, contributions to risk/reward judgments, promoting either exploitation of current favorable circumstances or exploration of more profitable ones when conditions change. In addition, phasic dopamine activity, regulated in part by the lateral habenula plays a key role in providing short-term information about recent outcomes that can bias subsequent choice behavior. These findings provide insight into the dynamic competition between these cortical/subcortical circuits that shape our decision biases and underlie conflicting urges when evaluating options that vary in terms of potential risks and rewards.
 
 
Learning Objectives
-Understand the functional connectivity between different cortical and subcortical systems that regulate different aspects of decision making in the context of reward seeking and
-Understand how different aspects of dopamine activity (modes of transmission, different receptor subtypes) regulate distinct aspects of action selection and reward processing.