Reward certainty and preference bias selectively shape voluntary decisions
Reward certainty and preference bias selectively shape voluntary decisions
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DOI：
10.1101/832311
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
Wojciech Zajkowski;D. Krzemiński;Jacopo Barone;Lisa H. Evans;Jiaxiang Zhang
中科院分区：
文献类型：
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作者：
Wojciech Zajkowski;D. Krzemiński;Jacopo Barone;Lisa H. Evans;Jiaxiang Zhang
在同等价值的选项之间进行选择可能是一个难题，经典决策理论预测，这将导致反应时间(RT)延长。矛盾的是，在这种情况下，理性的决策者不需要深思熟虑，因为替代方案的结果是无关紧要的。个人如何在平等的选择之间做出选择仍不清楚。在这里，我们通过在概率奖励任务中整合高级认知建模和脑电记录来表征这种自愿决定背后的神经认知过程，在这个任务中，人类参与者在与不同水平的相同奖励概率相关的一对线索中进行选择。我们发现，更高的奖赏确定性加速了反应时。在每个确定性水平上，参与者更喜欢选择一个线索，速度更快，频率更高。对RT的行为效应持续存在于对奖赏线索的简单反应中。通过对累加器模型的分层贝叶斯参数估计，我们发现确定性和偏好效应与决策过程中证据积累的速度独立相关，而与视觉编码或运动执行潜伏期无关。脑电诱发反应的时间分辨多变量模式分类早在刺激开始后120ms就发现了奖励确定性和偏好选择的显著表征，其中空间相关性模式在中央中电极和顶叶电极最大。此外，脑电信息的计算模型显示，N100和P300事件相关电位之间的变化率反映了在逐个审判的基础上由模型得出的证据积累速率的变化。我们的发现表明，奖励确定性和偏好共同塑造了平等选择之间的自愿决定，提供了一种防止犹豫不决或随机行为的机制。
Choosing between equally valued options can be a conundrum, for which classical decision theories predicted a prolonged response time (RT). Paradoxically, a rational decision-maker would need no deliberative thinking in this scenario, as outcomes of alternatives are indifferent. How individuals choose between equal options remain unclear. Here, we characterized the neurocognitive processes underlying such voluntary decisions, by integrating advanced cognitive modelling and EEG recording in a probabilistic reward task, in which human participants chose between pairs of cues associated with identical reward probabilities at different levels. We showed that higher reward certainty accelerated RT. At each certainty level, participants preferred to choose one cue faster and more frequently over the other. The behavioral effects on RT persisted in simple reactions to reward cues. By using hierarchical Bayesian parameter estimation for an accumulator model, we showed that the certainty and preference effects were independently associated with the rate of evidence accumulation during decisions, but not with visual encoding or motor execution latencies. Time-resolved multivariate pattern classification of EEG evoked response identified significant representations of reward certainty and preference choices as early as 120 ms after stimulus onset, with spatial relevance patterns maximal in middle central and parietal electrodes. Furthermore, EEG-informed computational modelling showed that the rate of change between N100 and P300 event-related potentials reflected changes in the model-derived rate of evidence accumulation on a trial-by-trial basis. Our findings suggested that reward certainty and preference collectively shaped voluntary decisions between equal options, providing a mechanism to prevent indecision or random behavior.