Making decision is an integral part of everyday life and we often need to make a decision under uncertainty. In the field of neuroeconomics, ambiguity means a condition in which the probabilities of different outcomes are unknown and previous studies showed that most people tend to exhibit some aversion to ambiguous components. However, less is known about the neural basis of decision making under ambiguity.
Twenty-four healthy volunteers participated in this study. We investigated the relationship between individual ambiguity aversion tendency and individual ambiguity intolerance tendency by a behavioral experiment and the Need for Closure Scale (NFCS). We also administered the self-report version of the Revised NEO Personality Inventory (NEO-PI-R). In addition, the neuroanatomical correlates of ambiguity aversion tendency were investigated by measuring the gray matter (GM) volume using voxel-based morphometry (VBM). Furthermore, we examined the associations between ambiguity aversion tendency and white matter (WM) integrity utilizing tract-based spatial statistics (TBSS).
The ambiguity aversion parameter measured by a decision-making task was not correlated with the score of ambiguity intolerance, one of the subscales of NFCS. However, ambiguity aversion parameter was associated with agreeableness score of NEO-PI-R. In addition, we found that the ambiguity aversion parameter was associated with GM volume in the inferior parietal lobule and the inferior frontal gyrus.
These results adds to our understanding of the neural mechanism involved in decision making under ambiguity.