Human midbrain sensitivity to cognitive feedback and uncertainty during classification learning
Human midbrain sensitivity to cognitive feedback and uncertainty during classification learning
复制标题
DOI：
10.1152/jn.01209.2003
复制
发表时间：
2004-08-01
影响因子：
2.5
通讯作者：
Poldrack, RA
中科院分区：
文献类型：
--
作者：
Aron, AR;Shohamy, D;Poldrack, RA
中脑多巴胺能系统（MDS）神经元可以通过向其目标（包括腹侧纹状体、眼眶和内侧额叶区域）提供预测误差信号，以及对与个体刺激相关的不确定性程度表现出敏感性来参与学习。我们使用功能磁共振成像研究了人类概率分类学习的机制，以检查反馈和不确定性的影响。该设计针对分离对刺激、延迟以及负反馈和正反馈分量的神经反应进行了优化。与固定相比，刺激和反馈激活的大脑区域与 MDS 一致，而延迟期则不然。负反馈与正反馈的中脑活动显着不同（与“预测误差”的编码一致），并且与不确定性程度以及 MDS 目标区域的活动可靠相关。纯粹的认知反馈显然涉及与奖励刺激相同的区域，这与该网络的更广泛的特征一致。
Mesencephalic dopaminergic system (MDS) neurons may participate in learning by providing a prediction error signal to their targets, which include ventral striatal, orbital, and medial frontal regions, as well as by showing sensitivity to the degree of uncertainty associated with individual stimuli. We investigated the mechanisms of probabilistic classification learning in humans using functional magnetic resonance imaging to examine the effects of feedback and uncertainty. The design was optimized for separating neural responses to stimulus, delay, and negative and positive feedback components. Compared with fixation, stimulus and feedback activated brain regions consistent with the MDS, whereas the delay period did not. Midbrain activity was significantly different for negative versus positive feedback (consistent with coding of the "prediction error") and was reliably correlated with the degree of uncertainty as well as with activity in MDS target regions. Purely cognitive feedback apparently engages the same regions as rewarding stimuli, consistent with a broader characterization of this network.