The interaction between expected values and risk levels in a modified Iowa gambling task.

Performance on the Iowa gambling task (IGT) supports somatic marker hypothesis (SMH), which proposes that the process of decision making depends on emotion (Damasio, 1994). However, the bad decks in the IGT are also more risky and that confounds the results. To resolve this issue, the IGT-Yen, a variant of the IGT, was created to independently examine the effects of expected value and risk. After 20 trials, participants selected more high-risk bad decks than low-risk bad decks and more low-risk good decks than high-risk good decks. Greater anticipatory skin conductance levels (SCLs) were associated with choosing high-risk bad decks compared to choosing low-risk bad decks in trials 21-80, and greater anticipatory SCLs were associated with choosing low-risk good decks compared to choosing high-risk good decks in trials 81-100. Therefore, the anticipatory SCLs were associated with expected values of the decks and with their levels of risk.