Researchers have discovered how a small brain structure plays a central role in the many decisions that we make each day such as what to order for lunch or whether to go with the hearty red wine or the lighter white.Studying how monkeys choose between juice drinks, the researchers found that some of the neurons in the orbitofrontal cortex (OFC) assign value to the options, while other neurons are related to making final choices. All of these neurons can re-map to make different decisions when circumstances change."When we choose between an apple and a banana, some neurons assign a value to the apple, some neurons assign a value to the banana, and other neurons represent the choice outcome," said the study's senior investigator Camillo Padoa-Schioppa from Washington University School of Medicine in St. Louis."Taken together, these different groups of cells seem to form a neural circuit that generates economic decisions," Padoa-Schioppa said.
In this study, reported in the journal Nature Neuroscience, the researchers examined how this neural circuit reorganises when decisions are made in different circumstances.During the experiments, the researchers used a dozen different juice drinks. In each tasting session, the monkeys chose between two different drinks. Subsequently, they chose between two other juice drinks."If we look at individual cells, neurons are very flexible," Padoa-Schioppa said."However, if we consider the whole network, the decision circuit is remarkably stable. This combination of circuit stability and neuronal flexibility makes it possible for the same brain region to generate decisions between any two goods," Padoa-Schioppa noted.