Breaking Deadlocks: Reward Probability and Spontaneous Preference Shape Voluntary Decisions and Electrophysiological Signals in Humans
Breaking Deadlocks: Reward Probability and Spontaneous Preference Shape Voluntary Decisions and Electrophysiological Signals in Humans
复制标题
DOI：
10.1007/s42113-020-00096-6
复制
发表时间：
2020-11
期刊：
影响因子：
--
通讯作者：
Wojciech Zajkowski;D. Krzemiński;Jacopo Barone;Lisa H. Evans;Jiaxiang Zhang
中科院分区：
文献类型：
--
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是一个常见的难题，经典决策理论预测，这将导致响应时间(RT)延长。这与稳定环境中的最优决策者应该做出快速而随机的选择的观念形成了鲜明对比，因为结果是无关紧要的。在这里，我们通过将行为反应的认知模型和脑电记录整合到一个概率奖励任务中来表征这种自愿决定背后的神经认知过程。人类参与者在与不同水平的相同奖励概率相关的明确线索对之间进行二元选择。更高的奖励概率加速了反应时，参与者在每个概率水平上选择一个线索的速度更快，频率也更高。对RT的行为效应持续存在于对单一线索的简单反应中。通过对累加器模型的分层贝叶斯参数估计，我们发现概率和偏好效应与证据积累速度的变化独立相关，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MVPA早在刺激开始后120ms就识别出显著的奖赏确定性和偏好，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，在逐个试验的基础上，N100和P300事件相关电位之间的变化速率调制了累积率。我们的发现表明，奖励概率和自发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 is a common conundrum, for which classical decision theories predicted a prolonged response time (RT). This contrasts with the notion that an optimal decision maker in a stable environment should make fast and random choices, as the outcomes are indifferent. Here, we characterize the neurocognitive processes underlying such voluntary decisions by integrating cognitive modelling of behavioral responses and EEG recordings in a probabilistic reward task. Human participants performed binary choices between pairs of unambiguous cues associated with identical reward probabilities at different levels. Higher reward probability accelerated RT, and participants chose one cue faster and more frequent over the other at each probability level. The behavioral effects on RT persisted in simple reactions to single cues. By using hierarchical Bayesian parameter estimation for an accumulator model, we showed that the probability and preference effects were independently associated with changes in the speed of evidence accumulation, but not with visual encoding or motor execution latencies. Time-resolved MVPA of EEG-evoked responses identified significant representations of reward certainty and preference 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 modulated accumulation rates on a trial-by-trial basis. Our findings suggest that reward probability and spontaneous preference collectively shape voluntary decisions between equal options, providing a mechanism to prevent indecision or random behavior.