Metzner Paul, von der Malsburg Titus, Vasishth Shravan, Rösler Frank
Department of Linguistics, University of Potsdam.
Department of Psychology and Department of Linguistics, University of California, San Diego.
Cogn Sci. 2017 May;41 Suppl 6:1232-1263. doi: 10.1111/cogs.12384. Epub 2016 Jun 16.
How important is the ability to freely control eye movements for reading comprehension? And how does the parser make use of this freedom? We investigated these questions using coregistration of eye movements and event-related brain potentials (ERPs) while participants read either freely or in a computer-controlled word-by-word format (also known as RSVP). Word-by-word presentation and natural reading both elicited qualitatively similar ERP effects in response to syntactic and semantic violations (N400 and P600 effects). Comprehension was better in free reading but only in trials in which the eyes regressed to previous material upon encountering the anomaly. A more fine-grained ERP analysis revealed that these regressions were strongly associated with the well-known P600 effect. In trials without regressions, we instead found sustained centro-parietal negativities starting at around 320 ms post-onset; however, these negativities were only found when the violation occurred in sentence-final position. Taken together, these results suggest that the sentence processing system engages in strategic choices: In response to words that don't match built-up expectations, it can either explore alternative interpretations (reflected by regressions, P600 effects, and good comprehension) or pursue a "good-enough" processing strategy that tolerates a deficient interpretation (reflected by progressive saccades, sustained negativities, and relatively poor comprehension).
自由控制眼球运动的能力对于阅读理解有多重要？句法分析器又是如何利用这种自由度的？我们通过将眼球运动与事件相关脑电位（ERP）进行共定位来研究这些问题，实验中参与者分别以自由阅读或计算机控制的逐字阅读格式（也称为快速序列视觉呈现，RSVP）进行阅读。逐字呈现和自然阅读在对句法和语义违反的反应中均引发了定性相似的ERP效应（N400和P600效应）。自由阅读时的理解更好，但仅限于在遇到异常情况时眼睛会回退到先前材料的试验中。更精细的ERP分析表明，这些回退与著名的P600效应密切相关。在没有回退的试验中，我们反而发现从开始后约320毫秒起持续出现中央顶叶负波；然而，这些负波仅在违反情况出现在句末位置时才被发现。综上所述，这些结果表明句子处理系统会进行策略选择：对于与已建立的预期不匹配的单词，它可以探索其他解释（由回退、P600效应和良好的理解反映），或者采用容忍不充分解释的“足够好”处理策略（由渐进扫视、持续负波和相对较差的理解反映）。
