How we make difficult decisions

New York, May 29, 2015: You must have felt dilemmas like whether to take a particular job - which was higher-paying, but away from your base town - or not. Such decisions, with both strong positives and negatives, arouse more anxiety than others. Now, Massachusetts Institute Of Technology (MIT) researchers have identified a neural circuit that appears to underlie decision-making in this type of situation, which is known as approach-avoidance conflict. The findings could help researchers to discover new ways to treat psychiatric disorders that feature impaired decision-making, such as depression, schizophrenia, and borderline personality disorder. "In order to create a treatment for these types of disorders, we need to understand how the decision-making process is working," said lead author Alexander Friedman. Friedman and colleagues also demonstrated the first step toward developing possible therapies for these disorders: By manipulating this circuit in rodents, they were able to transform a preference for lower-risk, lower-payoff choices to a preference for bigger payoffs despite their bigger costs. The new study grew out of an effort to figure out the role of striosomes -- clusters of cells distributed through the striatum, a large brain region involved in coordinating movement and emotion and implicated in some human disorders. Senior study author Ann Graybiel discovered striosomes many years ago, but their function had remained mysterious.