Ries S K, Piai V, Perry D, Griffin S, Jordan K, Henry R, Knight R T, Berger M S
School of Speech, Language, and Hearing Sciences, San Diego State University, United States; Center for Clinical and Cognitive Neuroscience, San Diego State University, United States; Joint Doctoral Program in Language and Communicative Disorders, San Diego State University and University of California San Diego, United States.
Radboud University, Donders Institute for Brain Cognition and Behaviour, Donders Centre for Cognition, Nijmegen, the Netherlands; Radboud University Medical Center, Donders Institute for Brain Cognition and Behaviour, Department of Medical Psychology, Nijmegen, the Netherlands.
Brain Lang. 2019 Apr;191:17-27. doi: 10.1016/j.bandl.2019.01.001. Epub 2019 Feb 12.
Human language is organized along two main processing streams connecting posterior temporal cortex and inferior frontal cortex in the left hemisphere, travelling dorsal and ventral to the Sylvian fissure. Some views propose a dorsal motor versus ventral semantic division. Others propose division by combinatorial mechanism, with the dorsal stream responsible for combining elements into a sequence and the ventral stream for forming semantic dependencies independent of sequential order. We acquired data from direct cortical stimulation in the left hemisphere in 17 neurosurgical patients and subcortical resection in a subset of 10 patients as part of awake language mapping. Two language tasks were employed: a sentence generation (SG) task tested the ability to form sequential and semantic dependencies, and a picture-word interference (PWI) task manipulated semantic interference. Results show increased error rates in the SG versus PWI task during subcortical testing in the dorsal stream territory, and high error rates in both tasks in the ventral stream territory. Connectivity maps derived from diffusion imaging and seeded in the tumor sites show that patients with more errors in the SG than in the PWI task had tumor locations associated with a dorsal stream connectivity pattern. Patients with the opposite pattern of results had tumor locations associated with a more ventral stream connectivity pattern. These findings provide initial evidence using fiber tract disruption with electrical stimulation that the dorsal pathways are critical for organizing words in a sequence necessary for sentence generation, and the ventral pathways are critical for processing semantic dependencies.
人类语言是沿着连接左半球颞叶后部皮质和额下皮质的两条主要加工流组织起来的，这两条加工流分别位于外侧裂的背侧和腹侧。一些观点提出存在背侧运动与腹侧语义的划分。另一些观点则提出按组合机制划分，背侧流负责将元素组合成序列，腹侧流负责形成独立于序列顺序的语义依赖关系。作为清醒语言映射的一部分，我们从17名神经外科患者左半球的直接皮质刺激以及10名患者亚组的皮质下切除术中获取了数据。采用了两项语言任务：句子生成（SG）任务测试形成序列和语义依赖关系的能力，图片-单词干扰（PWI）任务操纵语义干扰。结果显示，在背侧流区域的皮质下测试期间，SG任务的错误率高于PWI任务，而在腹侧流区域，两项任务的错误率都很高。从扩散成像得出并以肿瘤部位为种子点的连接图谱显示，在SG任务中比在PWI任务中错误更多的患者，其肿瘤位置与背侧流连接模式相关。结果呈现相反模式的患者，其肿瘤位置与更腹侧的流连接模式相关。这些发现利用纤维束破坏和电刺激提供了初步证据，表明背侧通路对于以句子生成所需的序列组织单词至关重要，而腹侧通路对于处理语义依赖关系至关重要。
