Payne Brennan, Federmeier Kara D
Department of Psychology, University of Utah, Salt Lake City, UT, USA.
Department of Psychology, Neuroscience Program, and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Word (N Y : 1945). 2019;65(4):252-272. doi: 10.1080/00437956.2019.1678826. Epub 2019 Nov 27.
In the current paper, we examined the effects of lexical (e.g. word frequency, orthographic neighborhood density) and contextual (e.g. word predictability in the form of cloze probability) features on single-trial event-related brain potentials in a self-paced reading paradigm. Critically, we examined whether individual differences in reading speed modulated single-trial effects on the N400, an ERP component linked to semantic memory access. Consistent with past work, we found that word frequency effects on the N400 were attenuated with increasing predictability. However, effects of orthographic neighborhood density were robust across all levels of predictability. Importantly, individual differences in reading speed moderated the influence of both frequency and predictability (but not orthographic neighborhood density) on the N400, such that slower readers showed reduced effects compared to faster readers. These data show that different lexical factors influence word processing through dissociable mechanisms. Our findings support a dynamic semantic-memory access model of the N400, in which information at multiple levels (lexical, sentential, individual) simultaneously contributes to the unfolding neural dynamics of comprehension.
在当前论文中，我们在自定步速阅读范式下，研究了词汇特征（如词频、正字法邻域密度）和语境特征（如以完形概率形式表示的词可预测性）对单次试验事件相关脑电位的影响。关键的是，我们研究了阅读速度的个体差异是否调节了对N400的单次试验效应，N400是一种与语义记忆提取相关的事件相关电位成分。与过去的研究一致，我们发现随着可预测性增加，词频对N400的效应减弱。然而，正字法邻域密度的效应在所有可预测性水平上都很稳健。重要的是，阅读速度的个体差异调节了频率和可预测性（但不是正字法邻域密度）对N400的影响，因此与阅读速度快的读者相比，阅读速度慢的读者效应更小。这些数据表明，不同的词汇因素通过可分离的机制影响词汇加工。我们的研究结果支持N400的动态语义记忆提取模型，其中多个层面（词汇、句子、个体）的信息同时促成理解过程中不断展开的神经动力学。
