Normal aging affects decisions under ambiguity, but not decisions under risk.

Old adults have to face many situations that require important decisions. In the present investigation, the authors examined the effects of aging on both decisions under ambiguity and decisions under risk. To this purpose, healthy young and old adults completed the Iowa Gambling Task (IGT) and the Probability-Associated Gambling task (PAG task). Old adults performed the PAG task as well as young adults, demonstrating ability to make decisions when full information about the problem situation, the options' probabilities and the associated gains and losses was given. Differently, old adults showed poor performance on the IGT relative to young adults, indicating difficulty in making advantageous decisions under ambiguous conditions. Indeed, in the IGT, participants are not aware of the rules for gains and losses and have to learn about the utility of their selections through experience. Results of our analyses point to the contribution of executive functions to all types of decisions. Our findings have also practical implications, suggesting that old people can make advantageous decisions when complete information about the decision situation is available.