Department of Psychology, Simon Fraser University, Burnaby, BC, Canada.
Brain Lang. 2010 Apr;113(1):39-44. doi: 10.1016/j.bandl.2010.01.008. Epub 2010 Feb 19.
Somatotopy within the orofacial region of the human motor cortex has been a central concept in interpreting the results of neuroimaging and transcranial magnetic stimulation studies of normal and disordered speech. Yet, somatotopy has been challenged by studies showing overlap among the effectors within the homunculus. In order to address this dichotomy, we performed four voxel-based meta-analyses of 54 functional neuroimaging studies of non-speech tasks involving respiration, lip movement, tongue movement, and swallowing, respectively. While the centers of mass of the clusters supported the classic homuncular view of the motor cortex, there was significant variability in the locations of the activation-coordinates among studies, resulting in an overlapping arrangement. This "somatotopy with overlap" might reflect the intrinsic functional interconnectedness of the oral effectors for speech production.
人类运动皮质的口面区域的躯体定位一直是解释正常和异常言语的神经影像学和经颅磁刺激研究结果的核心概念。然而,躯体定位受到了一些研究的挑战,这些研究表明在小人像内的效应器之间存在重叠。为了解决这一分歧,我们对涉及呼吸、唇动、舌动和吞咽的 54 项非言语任务的功能性神经影像学研究进行了四项基于体素的荟萃分析。虽然聚类的质心支持运动皮质的经典小人像观点,但在研究之间的激活坐标位置存在显著的可变性,导致重叠排列。这种“重叠的躯体定位”可能反映了言语产生的口腔效应器的内在功能连通性。