Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
Brain and Cognitive Engineering Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
PLoS Comput Biol. 2021 May 14;17(5):e1009003. doi: 10.1371/journal.pcbi.1009003. eCollection 2021 May.
Depression is characterized by deficits in the reinforcement learning (RL) process. Although many computational and neural studies have extended our knowledge of the impact of depression on RL, most focus on habitual control (model-free RL), yielding a relatively poor understanding of goal-directed control (model-based RL) and arbitration control to find a balance between the two. We investigated the effects of subclinical depression on model-based and model-free learning in the prefrontal-striatal circuitry. First, we found that subclinical depression is associated with the attenuated state and reward prediction error representation in the insula and caudate. Critically, we found that it accompanies the disrupted arbitration control between model-based and model-free learning in the predominantly inferior lateral prefrontal cortex and frontopolar cortex. We also found that depression undermines the ability to exploit viable options, called exploitation sensitivity. These findings characterize how subclinical depression influences different levels of the decision-making hierarchy, advancing previous conflicting views that depression simply influences either habitual or goal-directed control. Our study creates possibilities for various clinical applications, such as early diagnosis and behavioral therapy design.
抑郁症的特征是强化学习（RL）过程中出现缺陷。尽管许多计算和神经科学研究扩展了我们对抑郁症对 RL 影响的认识，但大多数研究都集中在习惯控制（无模型 RL）上，因此对目标导向控制（基于模型的 RL）和仲裁控制的理解相对较差，以在两者之间找到平衡。我们研究了亚临床抑郁症对前额叶-纹状体回路中基于模型和无模型学习的影响。首先，我们发现亚临床抑郁症与岛叶和尾状核中的衰减状态和奖励预测误差表示有关。至关重要的是，我们发现它伴随着主要在下外侧前额叶皮层和额极皮层中基于模型和无模型学习之间的仲裁控制的破坏。我们还发现，抑郁症削弱了利用可行选项的能力，称为利用敏感性。这些发现描述了亚临床抑郁症如何影响决策层次的不同级别，推进了先前相互矛盾的观点，即抑郁症只是简单地影响习惯或目标导向控制。我们的研究为各种临床应用创造了可能性，例如早期诊断和行为治疗设计。
