Center for Mind/Brain Sciences (CIMeC), University of Trento, Via delle Regole 101, 38123 Mattarello TN, Italy.
Neuroimage. 2013 May 1;71:59-74. doi: 10.1016/j.neuroimage.2013.01.003. Epub 2013 Jan 11.
To understand language, we integrate what we hear or read with prior context. This research investigates the neural systems underlying this integration process, in particular the integration of incoming linguistic information with local, proximal context and with global, distal context. The experiments used stories whose endings were locally consistent or locally inconsistent. In addition, the stories' global context was either relevant or irrelevant for the integration of the endings. In Experiment 1, reading latencies showed that the perceived consistency of an ending depended on its fit with the local context, but the availability of a relevant global context attenuated this effect. Experiment 2 used BOLD fMRI to study whether different neural systems are sensitive to the local consistency of the endings and the relevance of the global context. A first analysis evaluated BOLD responses during the comprehension of story endings. It identified three networks: one sensitive to consistency with local context, one sensitive to the relevance of the global context, and one sensitive to both factors. These findings suggest that some regions respond to the holistic relation of local and global contexts while others track only the global or the local contexts. A second analysis examined correlations between BOLD activity during listening of the story endings and subsequent memory for those endings. It revealed two distinct networks: Positive correlations in areas usually involved in semantic processing and memory for language, and negative correlations in sensory, motor, and visual areas, indicating that weaker activity in the latter regions is conducive to better memory for linguistic content. More widespread memory correlates were found when global context was relevant for understanding a story ending. We conclude that integration at the discourse level involves the cooperation of different networks each sensitive to separate aspects of the task, and that integration is more successfully achieved when the processing of potentially distracting information is reduced.
为了理解语言，我们将所听到或读到的内容与先前的语境相结合。本研究旨在探究这一整合过程背后的神经机制，特别是将输入的语言信息与局部、近端语境以及全局、远端语境相整合的过程。研究采用的故事结尾在局部上是一致的或不一致的。此外，故事的全局语境与结尾的整合要么相关，要么不相关。在实验 1 中，阅读潜伏期表明，结尾的感知一致性取决于其与局部语境的契合度，但相关全局语境的存在会削弱这种效应。实验 2 采用 BOLD fMRI 研究不同的神经机制对结尾局部一致性和全局语境相关性的敏感性。第一个分析评估了在理解故事结尾时 BOLD 反应。它确定了三个网络：一个对结尾与局部语境的一致性敏感，一个对全局语境的相关性敏感，还有一个对这两个因素都敏感。这些发现表明，一些区域对局部和全局语境的整体关系敏感，而其他区域只跟踪全局或局部语境。第二个分析考察了在聆听故事结尾时 BOLD 活动与随后对这些结尾的记忆之间的相关性。它揭示了两个不同的网络：与语义处理和语言记忆相关的区域呈正相关，而与感觉、运动和视觉区域呈负相关，这表明后者区域的活动较弱有助于更好地记忆语言内容。当全局语境有助于理解故事结尾时，会出现更广泛的记忆相关性。我们得出结论，在语篇层面上的整合涉及到不同网络的合作，每个网络都对任务的不同方面敏感，并且当处理潜在干扰信息的能力降低时，整合会更成功地实现。
