Ambiguity aversion in schizophrenia: An fMRI study of decision-making under risk and ambiguity

作者：Fujino Junya; Hirose Kimito; Tei Shisei; Kawada Ryosaku; Tsurumi Kosuke; Matsukawa Noriko; Miyata Jun; Sugihara Genichi; Yoshihara Yujiro; Ideno Takashi; Aso Toshihiko; Takemura Kazuhisa; Fukuyama Hidenao; Murai Toshiya; Takahashi Hidehiko^*

来源：Schizophrenia Research, 2016, 178(1-3): 94-101.

DOI：10.1016/j.schres.2016.09.006

• Schizophrenia
• Decision-making
• Functional magnetic resonance imaging
• Orbitofrontal cortex
• Risk
• Ambiguity

Whenmaking decisions in everyday life, we often have to choose between uncertain outcomes. Economic studies have demonstrated that healthy people tend to prefer options with known probabilities (risk) than those with unknown probabilities (ambiguity), which is referred to as "ambiguity aversion." However, it remains unclear how patients with schizophrenia behave under ambiguity, despite growing evidence of their altered decision-making under uncertainty. In this study, combining economic tools and functional magnetic resonance imaging (fMRI), we assessed the attitudes toward risk/ambiguity and investigated the neural correlates during decision-making under risk/ambiguity in schizophrenia. Although no significant difference in attitudes under risk was observed, patients with schizophrenia chose ambiguity significantly more often than the healthy controls. Attitudes under risk and ambiguity did not correlate across patients with schizophrenia. Furthermore, unlike in the healthy controls, activation of the left lateral orbitofrontal cortex was not increased during decision-making under ambiguity compared to under risk in schizophrenia. These results suggest that ambiguity aversion, a well-established subjective bias, is attenuated in patients with schizophrenia, highlighting the need to distinguish between risk and ambiguity when assessing decision-making under these situations. Our findings, comprising important clinical implications, contribute to improved understanding of the mechanisms underlying altered decision-making in patients with schizophrenia.

• 出版日期2016-12