Kotchoubey Boris, El-Khoury Sylvain
Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Germany.
Department of Ophthalmology, University Clinics of Mainz, Germany.
Brain Cogn. 2014 Dec;92C:48-60. doi: 10.1016/j.bandc.2014.10.007. Epub 2014 Oct 29.
The aim of the study was a comparison of lexical and contextual factors in understanding ambiguous words in German. First, a sample of native speakers selected 56 words having maximally strong differences between a dominant and a subordinate meaning. After this, another sample from the same population was visually presented with sentences that activated dominant or subordinate meanings of the words and were accompanied by probes associated with dominant or subordinate meanings. This resulted in a crossed design with two factors: sentence dominant vs. sentence subordinate and probe dominant vs. probe subordinate. An analysis of event-related brain potentials revealed a large, long-lasting and highly-significant N400 wave whenever the meaning of the probe was incongruent with the meaning of the sentence and the lack of this wave whenever the two meanings were congruent. In the typical N400 space and time, the effect was independent of whether the lexical word meaning was dominant or subordinate. At other sites and times, however (e.g., at lateral frontal electrodes F7/F8, and after 700ms), the congruence effect was significant after dominant sentences only. The data indicate that lexical factors have a rather limited influence on the activation of a particular meaning of ambiguous words. A strong context can virtually override even a very strong difference in the preference for different meanings.
该研究的目的是比较理解德语中歧义单词时的词汇和语境因素。首先，以母语者为样本，挑选出56个在主要意义和次要意义之间存在极大差异的单词。在此之后，从同一人群中抽取的另一个样本被视觉呈现一些句子，这些句子激活了单词的主要或次要意义，并伴有与主要或次要意义相关的探测词。这产生了一个具有两个因素的交叉设计：句子主要意义与句子次要意义，以及探测词主要意义与探测词次要意义。对事件相关脑电位的分析显示，每当探测词的意义与句子的意义不一致时，就会出现一个大的、持续时间长且高度显著的N400波，而当两种意义一致时则不会出现这个波。在典型的N400的空间和时间范围内，这种效应与词汇单词意义是主要意义还是次要意义无关。然而，在其他部位和时间（例如，在额叶外侧电极F7/F8处，以及700毫秒之后），一致性效应仅在主要意义的句子之后才显著。数据表明，词汇因素对歧义单词特定意义的激活影响相当有限。一个强大的语境实际上甚至可以超越不同意义偏好上的巨大差异。
