2014年4月16日水曜日

Neural Mechanisms of Gain–Loss Asymmetry in Temporal Discounting

Saori C. Tanaka, Katsunori Yamada, Hiroyasu Yoneda, and Fumio Ohtake

The Journal of Neuroscience, 16 April 2014, 34(16):5595-5602;

ヒトは将来の報酬を、損失に比べて、多く割り引くことが知られている(サイン効果)。
サイン効果が見られた被験者と見られなかった被験者の脳活動を比較すると、「報酬/損失の遅延時間に対する線条体の活動」及び「報酬/損失額に対する島皮質の活動」に違いがあることが分かった。

Humans typically discount future gains more than losses. This phenomenon is referred to as the “sign effect” in experimental and behavioral economics. Although recent studies have reported associations between the sign effect and important social problems, such as obesity and incurring multiple debts, the biological basis for this phenomenon remains poorly understood. Here, we hypothesized that enhanced loss-related neural processing in magnitude and/or delay representation are causes of the sign effect. We examined participants performing intertemporal choice tasks involving future gains or losses and compared the brain activity of those who exhibited the sign effect and those who did not. When predicting future losses, significant differences were apparent between the two participant groups in terms of striatal activity representing delay length and in insular activity representing sensitivity to magnitude. Furthermore, participants with the sign effect exhibited a greater insular response to the magnitude of loss than to that of gain, and also a greater striatal response to the delay of loss than to that of gain. These findings may provide a new biological perspective for the development of novel treatments and preventive measures for social problems associated with the sign effect.

0 件のコメント:

コメントを投稿