You Jiaxin, Saranpää Aino, Lindh-Knuutila Tiina, van Vliet Marijn, Salmelin Riitta
Department of Neuroscience and Biomedical Engineering, Aalto University, Aalto, Finland.
Aalto NeuroImaging, Aalto University, Aalto, Finland.
Hum Brain Mapp. 2025 Jun 1;46(8):e70247. doi: 10.1002/hbm.70247.
Literate humans can effortlessly interpret tens of thousands of words, even when the words are sometimes written incorrectly. This phenomenon suggests a flexible nature of reading that can endure a certain amount of noise. In this study, we investigated where and when brain responses diverged for conditions where misspelled words were resolved as real words or not. We used magnetoencephalography (MEG) to track the cortical activity as the participants read words with different degrees of misspelling that were perceived to range from real words to complete pseudowords, as confirmed by their behavioral responses. In particular, we were interested in how lexical information survives (or not) along the uncertainty spectrum, and how the corresponding brain activation patterns evolve spatiotemporally. We identified three brain regions that were notably modulated by misspellings: left ventral occipitotemporal cortex (vOT), superior temporal cortex (ST), and precentral cortex (pC). This suggests that resolving misspelled words into stored concepts involves an interplay between orthographic, semantic, and phonological processing. Temporally, these regions showed fairly late and sustained responses selectively to misspelled words. Specifically, an increasing level of misspelling increased the response in ST from 300 ms after stimulus onset; a functionally fairly similar but weaker effect was observed in pC. In vOT, misspelled words were sharply distinguished from real words, notably later, after 700 ms. A linear mixed effects (LME) analysis further showed that pronounced and long-lasting misspelling effects appeared first in ST and then in pC, with shorter-lasting activation also observed in vOT. We conclude that reading misspelled words engages brain areas typically associated with language processing, but in a manner that cannot be interpreted merely as a rapid feedforward mechanism. Instead, feedback interactions likely contribute to the late effects observed during misspelled-word reading.
有文化的人能够轻松理解数以万计的单词，即使这些单词有时拼写错误。这种现象表明阅读具有一种灵活的特性，能够承受一定程度的干扰。在本研究中，我们调查了在拼写错误的单词被识别为真实单词或未被识别的情况下，大脑反应在何处以及何时出现差异。我们使用脑磁图（MEG）来追踪参与者阅读不同程度拼写错误单词时的皮层活动，这些单词根据他们的行为反应被认为从真实单词到完全的假词不等。特别地，我们感兴趣的是词汇信息如何（或是否）在不确定性范围内留存，以及相应的大脑激活模式如何随时间和空间演变。我们确定了三个受拼写错误显著调节的脑区：左腹侧枕颞皮层（vOT）、颞上皮层（ST）和中央前皮层（pC）。这表明将拼写错误的单词解析为存储的概念涉及正字法、语义和语音处理之间的相互作用。在时间上，这些区域对拼写错误的单词表现出相当晚且持续的反应。具体而言，拼写错误程度的增加会使ST区在刺激开始后300毫秒的反应增强；在pC区观察到功能上相当相似但较弱的效应。在vOT区，拼写错误的单词在700毫秒后才与真实单词明显区分开来。线性混合效应（LME）分析进一步表明，明显且持久的拼写错误效应首先出现在ST区，然后出现在pC区，vOT区也观察到持续时间较短的激活。我们得出结论，阅读拼写错误的单词会激活通常与语言处理相关的脑区，但其方式不能仅仅解释为快速的前馈机制。相反，反馈相互作用可能导致了在阅读拼写错误单词时观察到的后期效应。
