Bonilha Leonardo, Hillis Argye E, Hickok Gregory, den Ouden Dirk B, Rorden Chris, Fridriksson Julius
Department of Neurology, Medical University of South Carolina, Charleston, SC, USA.
Department of Neurology, Johns Hopkins University, Baltimore, MD, USA.
Brain. 2017 Sep 1;140(9):2370-2380. doi: 10.1093/brain/awx169.
Auditory word comprehension is a cognitive process that involves the transformation of auditory signals into abstract concepts. Traditional lesion-based studies of stroke survivors with aphasia have suggested that neocortical regions adjacent to auditory cortex are primarily responsible for word comprehension. However, recent primary progressive aphasia and normal neurophysiological studies have challenged this concept, suggesting that the left temporal pole is crucial for word comprehension. Due to its vasculature, the temporal pole is not commonly completely lesioned in stroke survivors and this heterogeneity may have prevented its identification in lesion-based studies of auditory comprehension. We aimed to resolve this controversy using a combined voxel-based-and structural connectome-lesion symptom mapping approach, since cortical dysfunction after stroke can arise from cortical damage or from white matter disconnection. Magnetic resonance imaging (T1-weighted and diffusion tensor imaging-based structural connectome), auditory word comprehension and object recognition tests were obtained from 67 chronic left hemisphere stroke survivors. We observed that damage to the inferior temporal gyrus, to the fusiform gyrus and to a white matter network including the left posterior temporal region and its connections to the middle temporal gyrus, inferior temporal gyrus, and cingulate cortex, was associated with word comprehension difficulties after factoring out object recognition. These results suggest that the posterior lateral and inferior temporal regions are crucial for word comprehension, serving as a hub to integrate auditory and conceptual processing. Early processing linking auditory words to concepts is situated in posterior lateral temporal regions, whereas additional and deeper levels of semantic processing likely require more anterior temporal regions.10.1093/brain/awx169_video1awx169media15555638084001.
听觉词语理解是一个认知过程，涉及将听觉信号转化为抽象概念。传统上，对失语症中风幸存者进行的基于病变的研究表明，与听觉皮层相邻的新皮层区域主要负责词语理解。然而，最近关于原发性进行性失语症和正常神经生理学的研究对这一概念提出了挑战，表明左侧颞极对词语理解至关重要。由于其血管分布，颞极在中风幸存者中通常不会完全受损，这种异质性可能在基于病变的听觉理解研究中阻碍了对其的识别。我们旨在使用基于体素和结构连接组病变症状映射相结合的方法来解决这一争议，因为中风后的皮层功能障碍可能源于皮层损伤或白质断开连接。我们从67名慢性左半球中风幸存者那里获取了磁共振成像（基于T1加权和扩散张量成像的结构连接组）、听觉词语理解和物体识别测试。在排除物体识别因素后，我们观察到颞下回、梭状回以及一个包括左侧颞后区域及其与颞中回、颞下回和扣带回皮层连接的白质网络受损与词语理解困难有关。这些结果表明，颞叶后外侧和下部区域对词语理解至关重要，是整合听觉和概念处理的枢纽。将听觉词语与概念联系起来的早期处理位于颞叶后外侧区域，而更深层次的语义处理可能需要更靠前的颞叶区域。10.1093/brain/awx169_video1awx169media15555638084001
