PDF(Pubmed)
Abstract：
UNASSIGNED: Decision-making under risk is a common challenge. It is known that risk-taking behavior varies between contexts of reward and punishment, yet the mechanisms underlying this asymmetry in risk sensitivity remain unclear.
UNASSIGNED: This study used a monetary task to investigate neurochemical mechanisms and brain dynamics underpinning risk sensitivity. Twenty-eight participants engaged in a task requiring selection of visual stimuli to maximize monetary gains and minimize monetary losses. We modeled participant trial-and-error processes using reinforcement learning.
UNASSIGNED: Participants with higher subjective utility parameters showed risk preference in the gain domain (r = -0.59) and risk avoidance in the loss domain (r = -0.77). Magnetic resonance spectroscopy (MRS) revealed that risk avoidance in the loss domain was associated with γ-aminobutyric acid (GABA) levels in the ventral striatum (r = -0.42), but not in the insula (r = -0.15). Using functional magnetic resonance imaging (fMRI), we tested whether risk-sensitive brain dynamics contribute to participant risky choices. Energy landscape analyses demonstrated that higher switching rates between brain states, including the striatum and insula, were correlated with risk avoidance in the loss domain (r = -0.59), a relationship not observed in the gain domain (r = -0.02).
UNASSIGNED: These findings from MRS and fMRI suggest that distinct mechanisms are involved in gain/loss decision making, mediated by subcortical neurometabolite levels and brain dynamic transitions.
UNASSIGNED: This study used a monetary task to investigate neurochemical mechanisms and brain dynamics underpinning risk sensitivity. Twenty-eight participants engaged in a task requiring selection of visual stimuli to maximize monetary gains and minimize monetary losses. We modeled participant trial-and-error processes using reinforcement learning.
UNASSIGNED: Participants with higher subjective utility parameters showed risk preference in the gain domain (r = -0.59) and risk avoidance in the loss domain (r = -0.77). Magnetic resonance spectroscopy (MRS) revealed that risk avoidance in the loss domain was associated with γ-aminobutyric acid (GABA) levels in the ventral striatum (r = -0.42), but not in the insula (r = -0.15). Using functional magnetic resonance imaging (fMRI), we tested whether risk-sensitive brain dynamics contribute to participant risky choices. Energy landscape analyses demonstrated that higher switching rates between brain states, including the striatum and insula, were correlated with risk avoidance in the loss domain (r = -0.59), a relationship not observed in the gain domain (r = -0.02).
UNASSIGNED: These findings from MRS and fMRI suggest that distinct mechanisms are involved in gain/loss decision making, mediated by subcortical neurometabolite levels and brain dynamic transitions.
摘要：
■风险下的决策是一个共同的挑战。众所周知，冒险行为在奖励和惩罚的背景下有所不同，然而,这种风险敏感性不对称的潜在机制仍不清楚.
■这项研究使用了一项货币任务来研究神经化学机制和支撑风险敏感性的大脑动力学。28名参与者参与了一项任务，要求选择视觉刺激以最大化货币收益并最小化货币损失。我们使用强化学习对参与者的试错过程进行建模。
■主观效用参数较高的参与者在收益域（r=-0.59）中表现出风险偏好，在损失域（r=-0.77）中表现出风险规避。磁共振波谱（MRS）显示，损失域中的风险规避与腹侧纹状体中的γ-氨基丁酸（GABA）水平有关（r=-0.42），但不在脑岛(r=-0.15)。使用功能磁共振成像（fMRI），我们测试了风险敏感的大脑动力学是否有助于参与者的风险选择.能源景观分析表明，大脑状态之间的转换速率更高，包括纹状体和脑岛,与损失域中的风险规避相关(r=-0.59)，在增益域中没有观察到的关系(r=-0.02)。
■来自MRS和功能磁共振成像的这些发现表明，不同的机制参与了损益决策，由皮质下神经代谢水平和大脑动态转变介导。
■这项研究使用了一项货币任务来研究神经化学机制和支撑风险敏感性的大脑动力学。28名参与者参与了一项任务，要求选择视觉刺激以最大化货币收益并最小化货币损失。我们使用强化学习对参与者的试错过程进行建模。
■主观效用参数较高的参与者在收益域（r=-0.59）中表现出风险偏好，在损失域（r=-0.77）中表现出风险规避。磁共振波谱（MRS）显示，损失域中的风险规避与腹侧纹状体中的γ-氨基丁酸（GABA）水平有关（r=-0.42），但不在脑岛(r=-0.15)。使用功能磁共振成像（fMRI），我们测试了风险敏感的大脑动力学是否有助于参与者的风险选择.能源景观分析表明，大脑状态之间的转换速率更高，包括纹状体和脑岛,与损失域中的风险规避相关(r=-0.59)，在增益域中没有观察到的关系(r=-0.02)。
■来自MRS和功能磁共振成像的这些发现表明，不同的机制参与了损益决策，由皮质下神经代谢水平和大脑动态转变介导。
