Department of Neuroscience, Columbia University, New York, NY 10032.
INRIA, 33405 Talence, France.
Proc Natl Acad Sci U S A. 2017 Apr 18;114(16):E3315-E3323. doi: 10.1073/pnas.1613844114. Epub 2017 Apr 3.
In natural behavior, animals have access to multiple sources of information, but only a few of these sources are relevant for learning and actions. Beyond choosing an appropriate action, making good decisions entails the ability to choose the relevant information, but fundamental questions remain about the brain's information sampling policies. Recent studies described the neural correlates of seeking information about a reward, but it remains unknown whether, and how, neurons encode choices of instrumental information, in contexts in which the information guides subsequent actions. Here we show that parietal cortical neurons involved in oculomotor decisions encode, before an information sampling saccade, the reduction in uncertainty that the saccade is expected to bring for a subsequent action. These responses were distinct from the neurons' visual and saccadic modulations and from signals of expected reward or reward prediction errors. Therefore, even in an instrumental context when information and reward gains are closely correlated, individual cells encode decision variables that are based on informational factors and can guide the active sampling of action-relevant cues.
在自然行为中，动物可以获得多种信息来源，但这些来源中只有少数与学习和行动相关。做出明智的决策除了要选择适当的行动外，还需要能够选择相关的信息，但关于大脑的信息采样策略，仍存在一些基本问题。最近的研究描述了寻求有关奖励的信息的神经相关性，但尚不清楚神经元是否以及如何在信息指导后续行动的情况下，对工具性信息的选择进行编码。在这里，我们表明，参与眼球运动决策的顶叶皮层神经元在进行信息采样扫视之前，就会对扫视预期为后续动作带来的不确定性降低进行编码。这些反应与神经元的视觉和扫视调制以及预期奖励或奖励预测误差的信号不同。因此，即使在信息和奖励收益密切相关的工具性环境中，单个细胞也会编码基于信息因素的决策变量，并且可以指导对与行动相关的线索的主动采样。
