Department of Psychology, The Chinese University of Hong Kong, Hong Kong.
Department of Psychology, The Chinese University of Hong Kong, Hong Kong; Brain and Mind Institute, The Chinese University of Hong Kong, Hong Kong.
Neuropsychologia. 2020 Feb 3;137:107299. doi: 10.1016/j.neuropsychologia.2019.107299. Epub 2019 Dec 9.
How and when top-down information modulates visual-orthographic processing is an essential question in reading research. In a previous study, we showed that task modulation of print-tuning started at around 170 ms after stimulus presentation in the N1 offset of the ERP, while the N1 onset was yet unaffected. Here we test how prior category-level expectation affects visual-orthographic processing. Familiar, left/right-structured Chinese characters and stroke number matched, unfamiliar Korean characters were presented, while expectation about the upcoming stimuli was manipulated with green and blue colored frames (high Chinese vs. high Korean expectation). EEG data of 18 native Chinese speakers were recorded while participants performed an expectation judgment task. Results from occipito-temporal and whole map analyses revealed that effects of prior expectation changed throughout the N1. Accordingly in the N1 onset, a print tuning main effect was found, with a stronger N1 to Chinese characters than Korean characters, irrespective of expectation. In the N1 offset, an expectation-by-character interaction was observed at the whole map level, with a more negative N1 to Korean characters than Chinese characters when expecting a Chinese character, but no such difference when expecting a Korean character. Moreover, the expectation-by-character interaction continued to the N250, with similar responses to Chinese and Korean characters under the Chinese expectation condition, while less negative N250 to Korean than Chinese under the Korean expectation condition. Taken together, the current study provides evidence that prior category-level expectation starts to take effect at an early stage even within 200 ms by facilitating the processing of expected stimuli, suggesting that category-level expectation can influence early visual-orthographic processing during word recognition.
自上而下的信息如何以及何时调节视觉-拼字处理是阅读研究中的一个基本问题。在之前的研究中，我们表明，在 ERP 的 N1 偏移中，刺激呈现后约 170 毫秒开始对印刷品进行调制，而 N1 起始仍未受影响。在这里，我们测试了先前的类别级期望如何影响视觉-拼字处理。呈现熟悉的、左右结构的汉字和笔画数匹配的、不熟悉的韩语字符，同时通过绿色和蓝色边框来操纵对即将到来的刺激的期望（高中文与高韩语期望）。当参与者执行期望判断任务时，记录了 18 名母语为汉语的人的 EEG 数据。来自枕颞部和整个地图的分析结果表明，先前期望的影响在整个 N1 中发生了变化。相应地，在 N1 起始处，发现了印刷品调谐的主要效应，与韩语字符相比，对汉字的 N1 更强，而与期望无关。在 N1 偏移处，在整个地图水平上观察到了期望与字符的交互作用，当期望汉字时，对韩语字符的 N1 更负，但当期望韩语字符时则没有这种差异。此外，期望与字符的相互作用一直持续到 N250，在中文期望条件下，对中文和韩语字符的反应相似，而在韩文期望条件下，对韩文的 N250 反应则不那么消极。总之，本研究提供了证据表明，即使在 200 毫秒内，类别级别的期望也可以通过促进期望刺激的处理而开始生效，这表明类别级别的期望可以影响单词识别过程中的早期视觉-拼字处理。
