The psychological validity of non-adjacent collocations: Evidence from event-related brain potentials

我的博士论文的首要目标是找出大脑处理两个单词的方式是否有区别，第二个单词很可能跟在第一个单词后面（例如临床试验），而第二个单词不太可能跟在第一个单词后面（例如临床设备）。为了达到这个目的，我进行了一系列的四个EEG实验。EEG是“脑电图”的缩写，是一种将电极放置在参与者头皮上的方法。这些电极检测参与者在执行特定任务时的大脑活动。在我的实验中，任务是阅读在电脑屏幕上一次显示一个单词的句子。在这些句子中，我嵌入了两个单词对，其中第二个单词很可能跟在第一个单词后面（这些被称为搭配，或搭配双元图），以及两个单词对，其中第二个单词不可能跟在第一个单词后面（这些被称为非搭配，或非搭配双元图）。我的博士实验结果表明，大脑处理这两种不同类型的单词对的方式是不同的。当以英语为母语的人阅读非搭配双字时，他们的大脑似乎比阅读搭配双字时工作得更加努力。这是有道理的，因为读取一个非搭配的双字违反了对中第一个单词所设置的下一个单词可能出现的期望。研究结果还表明，当非英语母语者阅读非搭配的双字图时，他们的大脑似乎比英语母语者在同样的刺激下工作得更加努力。这可以通过考虑两组参与者对英语的接触程度来解释。以英语为母语的人以前可能遇到过非搭配词对，即使它们很少出现，而非以英语为母语的人以前可能从未遇到过这些词对。因此，从非母语者的角度来看，搭配违反可能更为极端。我的博士论文关注的是单词对而不是较长的单词序列，以减少可能影响单词序列处理方式的因素数量，从而使进行控制实验成为可能。然而，这实际上是对搭配概念的一种非常狭隘的概念化方式；在实践中，当一个词出现在另一个词的附近时，即使有几个中间词，即使这些词并不总是以相同的顺序出现，也被认为是形成搭配。因此，在我打算在奖学金期间进行的额外研究中，我将重点关注这些非相邻的搭配。具体来说，在最初的脑电图实验中，我的目标是找出大脑处理带有一个介入词的搭配的方式（例如，认真对待某事）与相同长度的匹配非搭配（例如，愉快地对待某事）相比是否存在差异。如果我发现有明显的处理差异，我就会进行另一个脑电图实验，这次是观察带有两个中间词的搭配（例如，take the matter seriously）。我将利用这两个实验的结果来设计研究问题和方法，以便在未来的工作中（在资助期之后）参与更多类型的搭配模式。我的发现，无论是现在的还是将来的，都将对我们理解语言是如何在大脑中运作的，以及对语言教学的实际方面有许多重要的影响（因为搭配教学是目前大多数高级语言学习者教学方法的主要部分）。

The overarching aim of my PhD thesis was to find out whether or not there is a difference in the way that the brain processes pairs of words where the second word is highly likely to follow the first word (e.g. clinical trials), compared to pairs of words where the second word is not likely to follow the first word (e.g. clinical devices). In order to achieve this aim, I carried out a series of four EEG experiments. EEG, short for "electroencephalography", is a method which involves placing electrodes across a participant's scalp. These electrodes detect the participant's brain activity while they are carrying out a particular task. In my experiments, the task was to read sentences presented one word at a time on a computer screen. Within these sentences, I embedded pairs of words where the second word is highly likely to follow the first word (these are known as collocations, or collocational bigrams), as well as pairs of words where the second word is not likely to follow the first word (these are known as non-collocations, or non-collocational bigrams).The results of my PhD experiments show that there is a difference in the way that the brain processes these two different types of word pairs. When native speakers of English read non-collocational bigrams, their brain seems to work much harder than when they read collocational bigrams. This makes sense, as reading a non-collocational bigram violates the expectation of which word is likely to come next that was set up by the first word in the pair. The results also show that, when non-native speakers of English read the non-collocational bigrams, their brain seems to work even harder than that of the native speakers of English exposed to the same stimuli. This can be explained by considering the amount of exposure that both participant groups have had to the English language. Native speakers are likely to have encountered the non-collocational word pairs before, even though they are highly infrequent, while non-native speakers have probably never encountered these word pairs before. The collocational violation is therefore likely to be more extreme from the perspective of a non-native speaker.My PhD thesis focused on word pairs rather than longer sequences of words in order to reduce the number of factors that might influence how the word sequences were processed, making it feasible to conduct controlled experiments. However, this is actually a very narrow way of conceptualizing the notion of collocation; in practice, words are considered to form collocations when they occur in one another's vicinity even if there are several intervening words, and even if the words do not always occur in the same order. In the additional research that I intend to undertake during the term of the Fellowship, I will therefore focus on these non-adjacent collocations. Specifically, in an initial EEG experiment, I aim to find out whether or not there is a difference in the way that the brain processes collocations with one intervening word (e.g. take something seriously), compared to matched non-collocations of the same length (e.g. take something happily). If I find that there is a distinct processing difference, I will then carry out another EEG experiment, this time looking at collocations with two intervening words (e.g. take the matter seriously). I will use the results of these two experiments to inform the design of research questions and methods for future work (after the funded period) engaging with yet more varied types of collocational pattern. My findings, present and to come, will have a number of key implications for both our understanding of how language works in the mind, and for practical aspects of language teaching (since the teaching of collocation is a major part of most current approaches to teaching advanced language learners).