Effects of dilemmas and aromas on performance of the Iowa Gambling Task.

Males outscore females on the original version of the Iowa Gambling Task (IGT). This may be due to differential regional prefrontal cortical activation by males and females during the task. PET imagery indicates increased activation in dorsolateral (DL) prefrontal cortex (PFC) in males and in medial orbital (ORB) PFC in females. A recent study reported that females' scores were elevated to the level of males' by having them deliberate moral dilemmas during the IGT. This was presumably due to a relative shift in PFC activation from medial ORB PFC to DL PFC areas. In the present study, after adding new participants and combining results from previous studies we failed to find a significant effect of deliberating dilemmas prior to or during the original IGT performance. However, the typical gender effect was replicated, as was the females' preference for cards from Deck B. The lack of dilemma-enhancement fails to support our previous suggestion of increasing activation in DL during the task. However, we investigated whether activation of ORB (also secondary olfactory cortex) would change IGT performance. When smelling novel aromas during the IGT, males' performance was reduced to the level of females whose performance was unchanged. This finding suggests that activation of emotional neural substrates might alter the dual cognitive (DL)/emotional (ORB) circuits that interact during decision-making.