École d'orthophonie et d'audiologie, Université de Montréal, Montréal, Canada.
Centre for Research on Brain, Language and Music, Montreal, Canada.
PLoS One. 2020 Mar 13;15(3):e0229169. doi: 10.1371/journal.pone.0229169. eCollection 2020.
In this event-related potential (ERP) study we reevaluate syntax-first approaches to sentence processing by implementing a novel paradigm in French that includes correct sentences, pure syntactic category violations, lexical-semantic anomalies, and combined anomalies. Our balanced design systematically controlled for target word (noun vs. verb) and the context immediately preceding it. Group results from 36 native speakers of Quebec French revealed that, up to 300 ms, ERPs elicited by syntactic category violations were comparable with ERP responses to correct sentences, showing that there is no early activation reflecting syntactic category identification. Instead, in response to all anomalous conditions, we observed an N400 followed by a P600. Combined anomalies yielded additive effects of syntactic category and lexical-semantic anomalies on the N400, and a large P600 effect similar to the one observed in the pure syntactic condition. These results provide strong evidence against the hypothesis that (i) syntactic categories are processed first, and (ii) that syntactic category errors "block" lexical-semantic processing. Further, the N400 effect in response to pure syntactic category violations reflects a mismatch detection between a predicted word-stem and the actual target. This mechanism takes place simultaneously (and potentially in parallel) with lexical-semantic processing. In contrast, an interaction of syntax and semantics for the P600 reveals that the same neurocognitive resources are recruited for syntactic and semantic integration, both promoted by the implementation of an acceptability judgement task in our design. Additional analyses of individual data complemented these observations: during sentence processing, participants did not rely on one single cognitive mechanism reflected by either the N400 or the P600 effect but on both, suggesting that the biphasic N400-P600 ERP wave can indeed be considered to be an index of phrase-structure violations in most individuals, at least if they are realized on content words.
在这项事件相关电位（ERP）研究中，我们通过在法语中实施一种新的范式，重新评估了以句法为优先的句子处理方法，该范式包括正确的句子、纯粹的句法类别违规、词汇语义异常和组合异常。我们的平衡设计系统地控制了目标词（名词与动词）和其前面的上下文。来自 36 名魁北克法语母语者的组结果显示，在 300 毫秒内，句法类别违规引发的 ERP 与正确句子的 ERP 反应相当，这表明没有反映句法类别识别的早期激活。相反，对于所有异常情况，我们观察到 N400 后跟着 P600。组合异常导致句法和词汇语义异常对 N400 的加性效应，以及类似于纯句法条件下观察到的大 P600 效应。这些结果强烈反对以下假设：(i) 句法类别首先被处理，以及 (ii) 句法类别错误“阻止”词汇语义处理。此外，对纯句法类别违规的 N400 效应反映了预测词干与实际目标之间的不匹配检测。这种机制与词汇语义处理同时（可能是并行）发生。相比之下，P600 对句法和语义的相互作用表明，相同的神经认知资源被用于句法和语义整合，这两种整合都由我们设计中的可接受性判断任务推动。对个体数据的额外分析补充了这些观察结果：在句子处理过程中，参与者不仅依赖于 N400 或 P600 效应所反映的一种单一认知机制，而是两者都依赖，这表明在大多数个体中，双相 N400-P600 ERP 波确实可以被视为短语结构违规的指标，至少如果它们在内容词上实现的话。
