SOCIAL LEARNING OF REWARD VALUE

该项目研究人类学习做出正确决策的最重要方式之一：通过观察他人。项目1研究我们如何评价社会和非社会刺激（社会奖励处理），项目2研究我们如何从其他人那里学习奖励（观察学习）。在项目1中研究的决策值和经验值的计算，在我们观察其他人时是否也发挥作用？如果是这样的话，他们是否招募了相同的大脑结构？四个具体目标系统地研究了观察学习背后的机制如何与直接经验学习背后的机制形成对比。第一个目标集中在一个结构，认为编码奖励预测错误的多巴胺能神经元，驱动学习，腹侧纹状体，并记录在猴子。第二个目标将这些研究扩展到人类，使用来自颅内记录的单单位和LFP数据，以及fMRI，并专注于多巴胺投射的靶结构：杏仁核和vmPFC。第三个目标是问，我们观察的对象究竟是谁，会有什么不同：这个人是否有能力，他们是朋友还是陌生人。这个目标关注的是腹侧纹状体、杏仁核和腹内侧前额叶皮层的这种调制。第四个目标探讨了在目标1和2下获得的fMRI数据与核心3下评估的心理变量之间可能存在的个体差异。

This Project investigates one of the most important ways in which humans learn to make sound decisions: through observing other people. Whereas Project 1 investigated how we value social and nonsocial stimuli (social reward processing), this Project 2 investigates how we learn from other people about rewards (observational learning). Do the same computations of decision values and experienced values that were investigated under Project 1 also come into play when we watch others? If so, do they recruit the same brain structures? Four Specific Aims systematically investigate how the mechanisms behind observational learning might contrast with the much better studied mechanisms behind learning from direct experience. The first Aim focuses on a structure thought to encode reward prediction errors in dopaminergic neurons that drive learning, the ventral striatum, and recordings in monkeys. The second Aim extends these studies to humans, using single-unit and LFP data from intracranial recordings, together with fMRI and focuses on the target structures of dopamine projections: amygdala and vmPFC. The third Aim asks what difference it might make exactly who we are observing: whether the person is competent or not, whether they are a friend or a stranger; this Aim looks at such modulation in the ventral striatum, the amygdala, and the ventromedial prefrontal cortex. The fourth Aim explores possible individual differences between the fMRI data obtained under Aims 1 and 2, and the psychological variables assessed under Core 3.