Abstract:
Cortical tracking, the synchronization of brain activity to linguistic rhythms is a well-established phenomenon. However, its nature has been heavily contested: Is it purely epiphenomenal or does it play a fundamental role in speech comprehension? Previous research has used intelligibility manipulations to examine this topic. Here, we instead varied listeners\' language comprehension skills while keeping the auditory stimulus constant. To do so, we tested 22 native English speakers and 22 Spanish/Catalan bilinguals learning English as a second language (SL) in an EEG cortical entrainment experiment and correlated the responses with the magnitude of the N400 component of a semantic comprehension task. As expected, native listeners effectively tracked sentential, phrasal, and syllabic linguistic structures. In contrast, SL listeners exhibited limitations in tracking sentential structures but successfully tracked phrasal and syllabic rhythms. Importantly, the amplitude of the neural entrainment correlated with the amplitude of the detection of semantic incongruities in SLs, showing a direct connection between tracking and the ability to understand speech. Together, these findings shed light on the interplay between language comprehension and cortical tracking, to identify neural entrainment as a fundamental principle for speech comprehension.
摘要:
皮质追踪,大脑活动与语言节奏的同步是一个公认的现象。然而,它的性质一直备受争议:它是纯粹的表观现象还是在言语理解中起着基本作用?先前的研究已经使用了清晰度操纵来检查这个话题。这里,相反,我们改变了听众的语言理解能力,同时保持听觉刺激恒定。要做到这一点,我们在EEG皮层夹带实验中测试了22名以英语为母语的人和22名学习英语作为第二语言(SL)的西班牙语/加泰罗尼亚语双语者,并将反应与语义理解任务的N400分量的大小相关联。不出所料,本地听众有效地跟踪了句子,短语,和音节语言结构。相比之下,SL听众在跟踪句子结构方面表现出局限性,但成功地跟踪了短语和音节节奏。重要的是,神经夹带的幅度与SL中语义不一致检测的幅度相关,显示了跟踪和理解语音的能力之间的直接联系。一起,这些发现揭示了语言理解和皮层跟踪之间的相互作用,将神经夹带识别为言语理解的基本原则。