Abstract: Iowa game task (IGT) is a common paradigm for examining the mechanisms on affective decision-making. Damasio and his colleagues hereby proposed the somatic marker hypothesis (SMH) to explain the neurophysiological mechanisms for the effect of emotion on decision-making. Recently, a wealth of evidence have been accumulated on whether the IGT is an ambiguous or a risky decision-making task, the relationship between emotion and cognition during IGT, and its links to working memory and declarative memory, as well as its neural network and molecular genetic mechanism. An ambiguous decision-making process could be dominant and the emotional somatic signals might play a significant role for guiding the preference for decision-making options during the early stage. However, a risky decision-making process could tend to emerge and the cognitive evaluation and expectation might gradually become dominant during the later stage. The processing for IGT has overlapping components with working memory and could also need declarative memory. IGT depend not only on activation of the emotion brain network composed by amygdala, ventromedial prefrontal cortex (vmPFC), orbitofrontal cortex (OFC), but also involve in dorsolateral prefrontal cortex (dLPFC), hippocampus, ventral striatum, insular cortex, pre-supplementary motor area (pre-SMA), cingulate cortex. The decision-making processing during IGT could be modulated by gene polymorphisms of COMT and 5-HTT. In short, the decision-making related to IGT requires the orchestration of multiple neural systems, and decisions made under ambiguity and risky may involve different genetic basis.

Key words: Iowa game task, affective decision-making, somatic marker hypothesis, ambiguous or risky decision-making, working memory, declarative memory, mechanisms of cognitive neuroscience