A common mechanism underlies changes of mind about decisions and confidence.
A common mechanism underlies changes of mind about decisions and confidence.
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DOI：
10.7554/elife.12192
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发表时间：
2016-02-01
期刊：
影响因子：
7.7
通讯作者：
Wolpert DM
中科院分区：
文献类型：
--
作者：
van den Berg R;Anandalingam K;Zylberberg A;Kiani R;Shadlen MN;Wolpert DM
决策伴随着对所选选项是否正确的一定程度的信心。顺序抽样框架解释了决策的速度和准确性，并自然扩展到对所做出的决策可能是正确的信心。然而，信心和准确性之间的差异表明，信心可能得到与决策过程分离的机制的支持。在这里，我们展示了这种差异可能是由于简单的处理延迟而自然产生的。当参与者被要求同时报告选择和信心时，他们的信心、反应时间和对运动的知觉决定通过有限的证据积累得到解释。然而，我们也观察到初始选择和/或信心的修订。这些想法的改变可以用导致最初选择的机制的延续来解释。我们的发现将序贯抽样框架扩展到对信心的摇摆不定，并促使人们在解释信心和准确性之间的分离时保持谨慎。DOI：http://dx.doi.org/10.7554/eLife.12192.001理解大脑是如何做出决定的，就是理解我们是如何思考的--我们如何处理信息，如何解释信息，并同意对信息的特定解释。神经科学已经开始通过将大脑中神经细胞的活动与决策的不同方面联系起来，来揭示这些过程背后的机制。这些因素包括需要多长时间才能做出决定，我们为什么会犯错，以及我们对决定的信心有多大。有时，当我们做出决定并承诺得到一个答案时，我们就会改变主意。现在，van den Berg等人。他们问到，支持改变想法的大脑机制是否也支持信心的改变。为了研究这个问题，人类志愿者被要求执行一项困难的任务，他们必须判断一个随机移动的点的区域是否有向左或向右漂移的趋势。在实验中，van den Berg等人。记录志愿者花了多长时间来做出决定，志愿者对他们的选择有多大的信心，以及他们是否正确。分析这些数据显示，所有这些措施都可以用一种机制来解释，即大脑只会积累证据，直到似乎有足够的证据支持其中一种选择。这个过程规定了一个人应该根据感官证据的质量和做出决定的时间来确定信心有多大。此外，van den Berg等人。研究发现，志愿者偶尔会改变主意，在做出决定后，他们对自己的信心有多大，就像他们一直在继续思考一样。尽管志愿者们没有收到更多关于这项任务的信息，也没有收到他们做出决定后做得有多好。因此，大脑似乎处理了已经被检测到但没有时间影响最初选择的额外信息。当志愿者做出决定时，大脑中神经细胞的活动没有被记录下来。未来结合这些测量的实验可能有助于揭示大脑如何执行必要的计算，并解释在处理某些数据时出现的时间延迟。这种延迟的信息在大脑中是在哪里处理的，它是如何导致想法改变的？DOI：http://dx.doi.org/10.7554/eLife.12192.002
Decisions are accompanied by a degree of confidence that a selected option is correct. A sequential sampling framework explains the speed and accuracy of decisions and extends naturally to the confidence that the decision rendered is likely to be correct. However, discrepancies between confidence and accuracy suggest that confidence might be supported by mechanisms dissociated from the decision process. Here we show that this discrepancy can arise naturally because of simple processing delays. When participants were asked to report choice and confidence simultaneously, their confidence, reaction time and a perceptual decision about motion were explained by bounded evidence accumulation. However, we also observed revisions of the initial choice and/or confidence. These changes of mind were explained by a continuation of the mechanism that led to the initial choice. Our findings extend the sequential sampling framework to vacillation about confidence and invites caution in interpreting dissociations between confidence and accuracy. DOI: http://dx.doi.org/10.7554/eLife.12192.001 To understand how the brain makes decisions is to understand how we think – how we deal with information, interpret it and agree with a particular interpretation of the information. Neuroscience has begun to uncover the mechanisms that underlie these processes by linking the activity of nerve cells in the brain to different aspects of making decisions. These include how long it takes to reach a decision, why we make errors and how confident we feel about a decision. Sometimes when we make a decision and have committed to an answer, we then change our minds. Now, van den Berg et al. have asked whether the brain mechanisms that support a change of mind also support a change in confidence. To investigate this problem, human volunteers were asked to perform a difficult task where they had to decide whether a field of randomly moving dots had a tendency to drift to the left or to the right. During the experiment, van den Berg et al. recorded how long the volunteers took to make their decision, how confident the volunteers felt about their choice, and whether they were correct. Analyzing this data revealed that all of these measures could be explained by a mechanism where the brain accumulates evidence only until there appears to be enough evidence to favor one choice over the other. This process specifies how confident an individual should be based on the quality of the sensory evidence and how long it takes to make a decision. In addition, van den Berg et al. found that occasionally a volunteer changed their mind about how confident they were about a decision after they’d made it, as if they had continued to think about it. This was despite the volunteers receiving no more information about the task or how well they had done once they had made their decision. Therefore, it appears that the brain processed additional information that had already been detected but did not have time to affect the initial choice. The activity of the nerve cells in the brain was not recorded as the volunteers made their decisions. Future experiments that incorporate these measurements could help reveal how the brain performs the necessary computations and account for the time delay seen in processing some of the data. Where is this delayed information processed in the brain, and how does it lead to a change of mind? DOI: http://dx.doi.org/10.7554/eLife.12192.002