Neural correlates, computation and behavioural impact of decision confidence
Neural correlates, computation and behavioural impact of decision confidence
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DOI：
10.1038/nature07200
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发表时间：
2008-09-11
期刊：
影响因子：
64.8
通讯作者：
Mainen, Zachary F.
中科院分区：
文献类型：
--
作者：
Kepecs, Adam;Uchida, Naoshige;Mainen, Zachary F.
人类和其他动物必须经常在不完美的证据的基础上做出决定（1，2）。统计学家使用诸如P值之类的度量来为命题分配置信度，但对大脑如何计算决策的置信度估计知之甚少。我们利用大鼠的行为分析和神经记录结合计算建模来探讨这个问题。受试者进行训练，以执行气味分类任务，允许决策的信心，通过改变测试刺激的类别边界的距离进行操纵。为了理解如何使用决策的标准模型（3 - 6）来沿着计算选择本身的置信度，我们定义了一个简单的度量，量化了有助于特定决策的证据的质量。在这里，我们发现眶额皮层中许多单个神经元的放电率与置信度模型的预测非常匹配，并且不能用其他机制来解释，例如学习刺激-结果关联（7 - 10）。此外，当使用延迟奖励版本的任务进行测试时，我们发现大鼠等待奖励的意愿随着信心的增加而增加，正如理论模型所预测的那样。这些结果表明，以前建议需要“元认知”（11，12）和有意识的意识（13，14）的置信度估计，即使在啮齿动物的大脑中也是可用的，可以用相对简单的操作计算，并且可以驱动适应性行为。我们认为，置信度估计可能是一个基本的和无处不在的组成部分的决策。
Humans and other animals must often make decisions on the basis of imperfect evidence(1,2). Statisticians use measures such as P values to assign degrees of confidence to propositions, but little is known about how the brain computes confidence estimates about decisions. We explored this issue using behavioural analysis and neural recordings in rats in combination with computational modelling. Subjects were trained to perform an odour categorization task that allowed decision confidence to be manipulated by varying the distance of the test stimulus to the category boundary. To understand how confidence could be computed along with the choice itself, using standard models of decision-making(3-6), we defined a simple measure that quantified the quality of the evidence contributing to a particular decision. Here we show that the firing rates of many single neurons in the orbitofrontal cortex match closely to the predictions of confidence models and cannot be readily explained by alternative mechanisms, such as learning stimulus - outcome associations(7-10). Moreover, when tested using a delayed reward version of the task, we found that rats' willingness to wait for rewards increased with confidence, as predicted by the theoretical model. These results indicate that confidence estimates, previously suggested to require 'metacognition'(11,12) and conscious awareness(13,14), are available even in the rodent brain, can be computed with relatively simple operations, and can drive adaptive behaviour. We suggest that confidence estimation may be a fundamental and ubiquitous component of decision- making.