Sara Morrison

To make effective decisions, people and animals must weigh both the benefits and costs of different courses of action. My lab studies the ways in which the brain integrates anticipated rewards and costs in different domains – e.g. time, risk, and physical effort – to arrive at a decision. We are also interested in the ways that the proximity of rewards and reward-related cues, whether in time or space, can interfere with adaptive decision-making by encouraging animals to make impulsive choices.

In order to study these processes, we use several techniques to measure and manipulate neuronal activity in rodents while they perform either simple reward learning or more complex decision-making tasks. We use in vivo electrophysiological recording to examine the task-related activity of single neurons in the prefrontal cortex, limbic structures (such as amygdala), and basal ganglia (especially nucleus accumbens). Both reward-related behavior and decision-making are highly influenced by dopamine; therefore, we also use pharmacological methods (e.g., targeted microinjections) and, more recently, optogenetic and chemogenetic techniques to study how dopamine release impacts both behavior and neural activity in these structures. In this way, we can shed light on the neural circuitry involved in healthy decision-making and better understand how the process goes awry under conditions that give rise to maladaptive decisions, including many psychiatric disorders.