Yamao Yukihiro, Matsumoto Riki, Kunieda Takeharu, Shibata Sumiya, Shimotake Akihiro, Kikuchi Takayuki, Satow Takeshi, Mikuni Nobuhiro, Fukuyama Hidenao, Ikeda Akio, Miyamoto Susumu
Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan.
Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine, Japan.
Cortex. 2015 May;66:134-40. doi: 10.1016/j.cortex.2014.11.008. Epub 2014 Dec 2.
Laughter consists of both motor and emotional aspects. The emotional component, known as mirth, is usually associated with the motor component, namely, bilateral facial movements. Previous electrical cortical stimulation (ES) studies revealed that mirth was associated with the basal temporal cortex, inferior frontal cortex, and medial frontal cortex. Functional neuroimaging implicated a role for the left inferior frontal and bilateral temporal cortices in humor processing. However, the neural origins and pathways linking mirth with facial movements are still unclear. We hereby report two cases with temporal lobe epilepsy undergoing subdural electrode implantation in whom ES of the left basal temporal cortex elicited both mirth and laughter-related facial muscle movements. In one case with normal hippocampus, high-frequency ES consistently caused contralateral facial movement, followed by bilateral facial movements with mirth. In contrast, in another case with hippocampal sclerosis (HS), ES elicited only mirth at low intensity and short duration, and eventually laughter at higher intensity and longer duration. In both cases, the basal temporal language area (BTLA) was located within or adjacent to the cortex where ES produced mirth. In conclusion, the present direct ES study demonstrated that 1) mirth had a close relationship with language function, 2) intact mesial temporal structures were actively engaged in the beginning of facial movements associated with mirth, and 3) these emotion-related facial movements had contralateral dominance.
笑包括运动和情感两个方面。情感成分，即愉悦，通常与运动成分相关联，也就是双侧面部运动。先前的皮层电刺激（ES）研究表明，愉悦与颞叶基底皮质、额下回皮质和额内侧皮质有关。功能神经影像学研究表明，左侧额下回和双侧颞叶皮质在幽默加工中发挥作用。然而，将愉悦与面部运动联系起来的神经起源和通路仍不清楚。我们在此报告两例接受硬膜下电极植入的颞叶癫痫患者，其中对左侧颞叶基底皮质进行电刺激时引发了愉悦以及与笑相关的面部肌肉运动。在一例海马正常的患者中，高频电刺激持续引起对侧面部运动，随后是伴有愉悦的双侧面部运动。相比之下，在另一例患有海马硬化（HS）的患者中，电刺激在低强度和短持续时间时仅引发愉悦，最终在高强度和长持续时间时引发笑。在这两例患者中，颞叶基底语言区（BTLA）位于电刺激产生愉悦的皮质内或其附近。总之，目前的直接电刺激研究表明：1）愉悦与语言功能密切相关；2）完整的内侧颞叶结构在与愉悦相关的面部运动开始时积极参与；3）这些与情感相关的面部运动具有对侧优势。
