Sackler Institute for Developmental Psychobiology, Weill Cornell Medical College, New York, NY, United States.
Brain Lang. 2011 Jul;118(1-2):23-8. doi: 10.1016/j.bandl.2011.02.006. Epub 2011 Mar 31.
There exists an increasing body of research demonstrating that language processing is aided by context-based predictions. Recent findings suggest that the brain generates estimates about the likely physical appearance of upcoming words based on syntactic predictions: words that do not physically look like the expected syntactic category show increased amplitudes in the visual M100 component, the first salient MEG response to visual stimulation. This research asks whether violations of predictions based on lexical-semantic information might similarly generate early visual effects. In a picture-noun matching task, we found early visual effects for words that did not accurately describe the preceding pictures. These results demonstrate that, just like syntactic predictions, lexical-semantic predictions can affect early visual processing around ∼100ms, suggesting that the M100 response is not exclusively tuned to recognizing visual features relevant to syntactic category analysis. Rather, the brain might generate predictions about upcoming visual input whenever it can. However, visual effects of lexical-semantic violations only occurred when a single lexical item could be predicted. We argue that this may be due to the fact that in natural language processing, there is typically no straightforward mapping between lexical-semantic fields (e.g., flowers) and visual or auditory forms (e.g., tulip, rose, magnolia). For syntactic categories, in contrast, certain form features do reliably correlate with category membership. This difference may, in part, explain why certain syntactic effects typically occur much earlier than lexical-semantic effects.
越来越多的研究表明，语言处理受到基于语境的预测的帮助。最近的研究结果表明，大脑根据句法预测生成关于即将出现的单词的可能物理外观的估计：看起来不符合预期句法类别的单词在视觉 M100 成分中表现出更高的振幅，这是对视觉刺激的第一个明显 MEG 反应。这项研究询问基于词汇语义信息的预测违反是否可能同样产生早期视觉效果。在图片-名词匹配任务中，我们发现与前面的图片不精确描述的单词有早期的视觉效果。这些结果表明，就像句法预测一样，词汇语义预测也可以影响大约 100ms 左右的早期视觉处理，这表明 M100 反应不仅仅针对与句法类别分析相关的视觉特征进行调整。相反，大脑可能会在任何时候对即将到来的视觉输入生成预测。然而，只有当可以预测单个词汇项时，词汇语义违反才会产生视觉效果。我们认为，这可能是因为在自然语言处理中，词汇语义字段（例如，花朵）和视觉或听觉形式（例如，郁金香、玫瑰、玉兰）之间通常没有直接的映射。相比之下，对于句法类别，某些形式特征确实与类别成员身份可靠相关。这种差异可能部分解释了为什么某些句法效应通常比词汇语义效应更早出现。
