Tonic exploration governs both flexibility and lapses
Tonic exploration governs both flexibility and lapses
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DOI：
10.1371/journal.pcbi.1007475
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发表时间：
2019-11-01
影响因子：
4.3
通讯作者：
Hayden, Benjamin Y.
中科院分区：
文献类型：
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作者：
Ebitz, R. Becket;Sleezer, Brianna J.;Hayden, Benjamin Y.
在许多认知任务中，失误（自发错误）被默认为有害过程的结果，如感觉运动噪音、疲劳或脱离接触。然而，一些失误也可能是由探索性噪音引起的：在不断变化的环境中促进学习的行为的随机性。如果是这样，那么战略过程只需要上调（而不是产生）探索以适应不断变化的环境。这种观点预测，更频繁的失误应该与更大的灵活性相关联，因为这些行为有一个共同的原因。在这里，我们报告说，当恒河猴执行一个集合转移任务时，失误率与持续错误频率负相关，这与探索的共同基础一致。这些结果不能用当地学习失败来解释。此外，长期暴露于可卡因（已知会损害认知灵活性）确实增加了持续性错误，但令人惊讶的是，它也通过减少失误率提高了整体的设置转移任务表现。我们将这些结果与状态切换模型相协调，在该模型中，可卡因通过加深与规则状态相对应的吸引盆地来减少勘探。这些结果支持了这样一种观点，即探索性噪音会导致失误，即使在没有战略价值的情况下也会影响基于规则的决策，并表明调节探索的一个关键机制可能是规则状态的深度。我们为什么会犯错误？我们似乎有能力确定最好的行动方案，但我们并不总是选择它。在这里，我们报告说，至少有一些错误是由于探索——一种专注于发现和学习的决策，而不是选择最佳选择。这是令人惊讶的，因为许多关于探索的观点都认为探索只会阶段性地发生——当环境建议你放弃之前的行动并制定新计划时。然而，在这里，我们发现有证据表明，无论改变是有益的还是错误的，探索都会促使你做出改变行为的决定。我们需要做更多的工作来理解为什么我们会进行强直性探索，但有可能强直性探索在进化过程中非常有用，以至于我们的大脑进化到今天继续探索，即使它在当下没有战略上的好处。例如，一个用于探索的补益算法可以减少我们做决定或准备利用意外机会所需的努力。
In many cognitive tasks, lapses (spontaneous errors) are tacitly dismissed as the result of nuisance processes like sensorimotor noise, fatigue, or disengagement. However, some lapses could also be caused by exploratory noise: randomness in behavior that facilitates learning in changing environments. If so, then strategic processes would need only up-regulate (rather than generate) exploration to adapt to a changing environment. This view predicts that more frequent lapses should be associated with greater flexibility because these behaviors share a common cause. Here, we report that when rhesus macaques performed a set-shifting task, lapse rates were negatively correlated with perseverative error frequency across sessions, consistent with a common basis in exploration. The results could not be explained by local failures to learn. Furthermore, chronic exposure to cocaine, which is known to impair cognitive flexibility, did increase perseverative errors, but, surprisingly, also improved overall set-shifting task performance by reducing lapse rates. We reconcile these results with a state-switching model in which cocaine decreases exploration by deepening attractor basins corresponding to rule states. These results support the idea that exploratory noise contributes to lapses, affecting rule-based decision-making even when it has no strategic value, and suggest that one key mechanism for regulating exploration may be the depth of rule states.Author summary Why do we make mistakes? We seem to have the capacity to identify the best course of action, but we do not always choose it. Here, we report that at least some mistakes are due to exploration-a type of decision-making that is focused on discovery and learning, rather than on choosing the best option. This is surprising because many views of exploration assume that exploration only happens phasically-when the circumstances suggest that you should abandon your previous course of action and make a new plan. However, here, we find evidence that exploration drives decisions to change your behavior both when change is helpful and when it is a mistake. More work is needed to understand why we explore tonically, but it is possible that tonic exploration may been so useful over evolutionary time that our brains evolved to continue to explore today, even when it has no strategic benefit in the moment. For example, a tonic algorithm for exploration could reduce the effort required to make decisions or prepare us to take advantage of unexpected opportunities.