Stowe Laurie A, Paans Anne M J, Wijers Albertus A, Zwarts Frans
Department of Linguistics, Graduate School of Behavioral and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands.
Brain Lang. 2004 May;89(2):290-9. doi: 10.1016/S0093-934X(03)00359-6.
In this paper we report the results of an experiment in which subjects read syntactically unambiguous and ambiguous sentences which were disambiguated after several words to the less likely possibility. Understanding such sentences involves building an initial structure, inhibiting the non-preferred structure, detecting that later input is incompatible with the initial structure, and reactivating the alternative structure. The ambiguous sentences activated four areas more than the unambiguous sentences. These areas are the left inferior frontal gyrus (IFG), the right basal ganglia (BG), the right posterior dorsal cerebellum (CB) and the left median superior frontal gyrus (SFG). The left IFG is normally activated when syntactic processing complexity is increased and probably supports that function in the current study as well. We discuss four hypotheses concerning how these areas may support comprehension of syntactically ambiguous sentences. (1) The left IFG, right CB and BG could support articulatory rehearsal used to support the processing of ambiguous sentences. This seems unlikely since the activation pattern associated with articulatory rehearsal in other studies is not similar to that seen here. (2) The CB acts as an error detector in motor processing. Error detection is important for recognizing that the wrong sentence structure has been chosen initially. (3) The BG acts to select and sequence movements in the motor domain and in cognitive domains may serve to inhibit competing and completed plans which is not unlike inhibiting the initially non-preferred structure or "unchoosing" the initial choice when incompatible syntactic input is received. (4) The left median SFG is relevant for the evaluation of plausibility. Evaluating the plausibility of the two possibilities provides an important basis for choosing between them. The notion of the use of domain general cognitive processes to support a linguistic process is in line with recent suggestions that the a given area may subserve a specific cognitive task because it carries out an appropriate sort of computation rather than because it supports a specific cognitive domain.
在本文中，我们报告了一项实验的结果。在该实验中，受试者阅读句法明确和不明确的句子，这些句子在几个词之后被消除歧义，使其成为可能性较小的那种解读。理解此类句子需要构建一个初始结构，抑制非优选结构，检测后来的输入与初始结构不兼容，并重新激活替代结构。与明确句子相比，歧义句子激活了四个更多的脑区。这些脑区是左侧额下回（IFG）、右侧基底神经节（BG）、右侧后背部小脑（CB）和左侧额上回中部（SFG）。当句法处理复杂性增加时，左侧额下回通常会被激活，在当前研究中它可能也支持该功能。我们讨论了关于这些脑区如何支持对句法歧义句子理解的四个假设。（1）左侧额下回、右侧小脑和基底神经节可能支持用于辅助处理歧义句子的发音复述。但这似乎不太可能，因为在其他研究中与发音复述相关的激活模式与这里观察到的不同。（2）小脑在运动处理中充当错误检测器。错误检测对于识别最初选择了错误的句子结构很重要。（3）基底神经节在运动领域中用于选择和排序动作，在认知领域中可能用于抑制相互竞争和已完成的计划，这与在接收到不兼容的句法输入时抑制最初的非优选结构或“取消”初始选择并无不同。（4）左侧额上回中部与合理性评估相关。评估两种可能性的合理性为在它们之间进行选择提供了重要依据。使用领域通用认知过程来支持语言过程的观点与最近的一些观点一致，即给定区域可能服务于特定的认知任务，是因为它执行了适当类型的计算，而不是因为它支持特定的认知领域。
