Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Cognitive Brain Research Unit, Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
Psychophysiology. 2018 Nov;55(11):e13216. doi: 10.1111/psyp.13216. Epub 2018 Aug 13.
While previous studies on language processing highlighted several ERP components in relation to specific stages of sound and speech processing, no study has yet combined them to obtain a comprehensive picture of language abilities in a single session. Here, we propose a novel task-free paradigm aimed at assessing multiple levels of speech processing by combining various speech and nonspeech sounds in an adaptation of a multifeature passive oddball design. We recorded EEG in healthy adult participants, who were presented with these sounds in the absence of sound-directed attention while being engaged in a primary visual task. This produced a range of responses indexing various levels of sound processing and language comprehension: (a) P1-N1 complex, indexing obligatory auditory processing; (b) P3-like dynamics associated with involuntary attention allocation for unusual sounds; (c) enhanced responses for native speech (as opposed to nonnative phonemes) from ∼50 ms from phoneme onset, indicating phonological processing; (d) amplitude advantage for familiar real words as opposed to meaningless pseudowords, indexing automatic lexical access; (e) topographic distribution differences in the cortical activation of action verbs versus concrete nouns, likely linked with the processing of lexical semantics. These multiple indices of speech-sound processing were acquired in a single attention-free setup that does not require any task or subject cooperation; subject to future research, the present protocol may potentially be developed into a useful tool for assessing the status of auditory and linguistic functions in uncooperative or unresponsive participants, including a range of clinical or developmental populations.
虽然先前有关语言处理的研究强调了与声音和语音处理特定阶段相关的几个 ERP 成分，但尚无研究将它们结合起来，以在单次会议中获得语言能力的综合图像。在这里，我们提出了一种新颖的无任务范式，旨在通过在多特征被动Oddball 设计的改编中结合各种语音和非语音声音来评估语音处理的多个层次。我们记录了健康成年参与者的 EEG，他们在进行主要视觉任务的同时，在没有声音引导注意力的情况下接受了这些声音。这产生了一系列反应，反映了各种声音处理和语言理解水平：（a）P1-N1 复合体，指示强制性听觉处理；（b）与不寻常声音的非自愿注意力分配相关的 P3 样动力学；（c）与非母语音素相比，对母语语音（而不是非母语音素）的响应增强，从音素开始约 50 毫秒，指示语音处理；（d）熟悉的真实单词相对于无意义的假词的振幅优势，指示自动词汇访问；（e）动作动词与具体名词的皮层激活的拓扑分布差异，可能与词汇语义处理有关。这些语音处理的多个指标是在单个无需注意力的设置中获得的，该设置不需要任何任务或主体合作；受未来研究的限制，本方案可能会发展成为评估非合作或无反应参与者（包括一系列临床或发育人群）的听觉和语言功能状态的有用工具。
