Current computational and neuroscientific models of decision-making posit a discrete, serial processing distinction between upstream decisional stages and downstream processes of motor-response implementation. We investigated this framework in the context of two-alternative forced-choice tasks on linguistic stimuli, words and pseudowords. In two experiments, we assessed the impact of lexical frequency and action semantics on two effector-selective EEG indexes of motor-response activation: the lateralized readiness potential and the lateralization of beta-frequency power. This allowed us to track potentially continuous streams of processing progressively mapping the evaluation of linguistic stimuli onto corresponding response channels. Whereas action semantics showed no influence on EEG indexes of motor-response activation, lexical frequency affected the lateralization of response-locked beta-frequency power. We argue that these observations point toward a continuity between linguistic processing of word input stimuli and implementation of corresponding choice in terms of motor behavior. This interpretation challenges the commonly held assumption of a discrete processing distinction between decisional and motor-response processes in the context of decisions based on symbolic stimuli.

当前的计算和神经科学决策模型假定上游决策阶段和下游运动反应实施过程之间存在离散的、连续的处理区别。我们在关于语言刺激、单词和伪词的两种可选强制选择任务的背景下研究了这个框架。在两个实验中，我们评估了词汇频率和动作语义对运动反应激活的两个效应器选择性 EEG 指标的影响：侧化准备潜力和 β 频率功率的侧化。这使我们能够跟踪潜在的连续处理流，逐步将语言刺激的评估映射到相应的响应通道。而动作语义对运动反应激活的脑电图指标没有影响，词汇频率影响响应锁定β频率功率的偏侧化。我们认为，这些观察指向单词输入刺激的语言处理与在运动行为方面的相应选择的实施之间的连续性。这种解释挑战了普遍持有的假设，即在基于符号刺激的决策背景下，决策过程和运动反应过程之间存在离散处理区别。