MYOPIA FOR THE FUTURE OR HYPERSENSITIVITY TO REWARD? AGE-RELATED CHANGES IN DECISION-MAKING ON THE IOWA GAMBLING TASK

摘要

It has been shown that older adults perform less well than younger adults on the Iowa Gambling Task (IGT), a real-world type decision-making task that factors together reward, punishment, and uncertainty. To explore the reasons behind this age-related decrement, we administered to an adult life-span sample of 265 healthy participants (median age = 62.00 +/− 16.17 years; range [23–88]) two versions of the IGT, which have different contingencies for successful performance: A'B'C'D' requires choosing lower immediate reward (paired with lower delayed punishment); E'F'G'H' requires choosing higher immediate punishment (paired with higher delayed reward). There was a significant negative correlation between age and performance on the A'B'C'D' version of the IGT (r = −.16, p = .01), while there was essentially no correlation between age and performance on the E'F'G'H' version (r = −.07, p = .24). In addition, the rate of impaired performance in older participants was significantly higher for the A'B'C'D' version (23%), compared to the E'F'G'H' version (13%). A parsimonious account of these findings is an age-related increase in hypersensitivity to reward, whereby the decisions of older adults are disproportionately influenced by prospects of receiving reward, irrespective of the presence or degree of punishment.