Hauk Olaf, Marchive Marion, Volfart Angelique, Schiltz Christine, Rossion Bruno, Ralph Matthew A Lambon, Lochy Aliette
MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom.
Institute of Cognitive Science and Assessment, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
Imaging Neurosci (Camb). 2025 Jan 3;3. doi: 10.1162/imag_a_00414. eCollection 2025.
Fast periodic visual stimulation (FPVS) allows the objective measurement of brain responses of human word discrimination (i.e., reproducible word-category-selective responses) with a high signal-to-noise ratio. This approach has been successfully employed over the last decade in a number of scalp electroencephalography (EEG) studies. Three important advances for research on word-selective brain responses were achieved in the present study: (1) we extend previous evidence of robust word-category-selective responses to the English language, (2) report results for combined EEG and MEG signals, and (3) source estimation results. English words were presented periodically (2 Hz) among different types of letter strings (10 Hz; consonant strings, non-words, pseudo-words) while recording simultaneous EEG and MEG in 25 participants who performed a simple non-linguistic colour detection task. Data were analysed in sensor and in source space. With only 4 minutes of stimulation, we observed a robust word discrimination response in each condition, even when words were embedded in sequences of word-like pseudo-words. This response was larger in non-words and largest in consonant strings. We observed left-lateralised responses in all conditions in the majority of our participants. Cluster-based permutation tests revealed that these responses were left-lateralised in sensor as well as in source space, with peaks in left posterior regions. Our results demonstrate that the FPVS approach can elicit robust English word discrimination responses in EEG and MEG within only a few minutes of recording time. Together with source estimation, this can provide novel insights into the neural basis of visual word recognition in healthy and clinical populations.
快速周期性视觉刺激（FPVS）能够以高信噪比客观测量人类单词辨别过程中的大脑反应（即可重复的单词类别选择性反应）。在过去十年中，这种方法已成功应用于多项头皮脑电图（EEG）研究。本研究在单词选择性大脑反应研究方面取得了三项重要进展：（1）我们将先前关于强大的单词类别选择性反应的证据扩展到了英语；（2）报告了脑电图和脑磁图（MEG）信号联合分析的结果；（3）源估计结果。在25名参与者执行简单的非语言颜色检测任务时，以2赫兹的频率周期性呈现英语单词，同时记录脑电图和脑磁图，单词夹杂在不同类型的字母串（10赫兹；辅音串、非单词、伪单词）中。对传感器空间和源空间中的数据进行了分析。仅经过4分钟的刺激，我们就在每种条件下观察到了强大的单词辨别反应，即使单词嵌入在类似单词的伪单词序列中。这种反应在非单词中更大，在辅音串中最大。在大多数参与者的所有条件下，我们都观察到了左侧化反应。基于聚类的置换检验表明，这些反应在传感器空间和源空间中均为左侧化，峰值出现在左后区域。我们的结果表明，FPVS方法能够在仅几分钟的记录时间内，在脑电图和脑磁图中引发强大的英语单词辨别反应。结合源估计，这可以为健康人群和临床人群视觉单词识别的神经基础提供新的见解。
