Common and Distinct Reward and Punishment Systems in the Human Brain

California Institute Of Technology, Pasadena CA

Investigators

Abstract

In the course of everyday life, people are frequently faced with decisions between different goals. Often these involve choices between different types of rewards. For example, should I spend extra hours at work to get that salary bonus, or should I spend that time instead to be with my family? In order to develop an understanding of how the brain computes decisions between different types of reward it is necessary to first determine how each of these different types of reward are represented in the brain. The goals of this project are to determine whether different rewards are represented in different brain areas, and whether there also exists a system that responds similarly to different types of reward. With support from the National Science Foundation, Dr. John O'Doherty and colleagues at the California Institute of Technology will address these questions by using brain imaging techniques (functional magnetic resonance imaging) to probe neural responses to rewards and punishments in a number of key brain regions known to be involved in processing of emotional responses and rewards, including the amygdala, orbitofrontal cortex, ventral striatum and anterior insula. A series of experiments will be conducted during which human volunteers will be presented with two different types of reward and punishment: juice (pleasant and aversive) and money (wins and losses), interleaved within the same experiments. These responses will then be compared directly to test for regions responding to both types of reward or punishment, as well as to determine regions that respond exclusively to one or other type. Brain responses will be measured not only to the receipt of reward, but also to their expectation. This work will result in a more comprehensive picture of reward and punishment representations in the human brain. The research could also provide insights into the mechanisms underlying complex decision making behaviors that depend on integration of different types of reward information. The findings generated by this research could help elucidate the fundamental learning mechanisms that underlie all motivated behaviors. Such findings could have a significant impact on fields outside cognitive neuroscience such as economics and decision theory. This research could also lead to the development of novel techniques to help people make better decisions, or improve learning and skill acquisition through the use of reinforcement. The funding from this application will be used to support a new research group at Caltech which can provide research training opportunities for undergraduate, graduate and post-doctoral trainees in cognitive neuroscience and brain imaging.