Action and Cognition Laboratory, Adam Mickiewicz University, Poznan, Poland; Faculty of Psychology and Cognitive Science, Adam Mickiewicz University, Poznan, Poland.
Action and Cognition Laboratory, Adam Mickiewicz University, Poznan, Poland.
Cortex. 2021 Jul;140:110-127. doi: 10.1016/j.cortex.2021.03.022. Epub 2021 Apr 20.
While Liepmann was one of the first researchers to consider a relationship between skilled manual actions (praxis) and language for tasks performed "freely from memory", his primary focus was on the relations between the organization of praxis and left-hemisphere dominance. Subsequent attempts to apply his apraxia model to all cases he studied - including his first patient, a "non-pure right-hander" treated as an exception - left the praxis-handedness issue unresolved. Modern neuropsychological and recent neuroimaging evidence either showed closer associations of praxis and language, than between handedness and any of these two functions, or focused on their dissociations. Yet, present-day developments in neuroimaging and statistics allow us to overcome the limitations of the earlier work on praxis-language-handedness links, and to better quantify their interrelationships. Using functional magnetic resonance imaging (fMRI), we studied tool use pantomimes and subvocal word generation in 125 participants, including righthanders (N = 52), ambidextrous individuals (mixedhanders; N = 31), and lefthanders (N = 42). Laterality indices were calculated both in two critical cytoarchitectonic maps, and 180 multi-modal parcellations of the human cerebral cortex, using voxel count and signal intensity, and the most relevant regions of interest and their networks were further analyzed. We found that atypical organization of praxis was present in all handedness groups (RH = 25.0%, MH = 22.6%; LH = 45.2%), and was about two and a half times as common as atypical organization of language (RH = 3.8%; MH = 6.5%; LH = 26.2%), contingent on ROI selection/LI-calculation method. Despite strong associations of praxis and language, regardless of handedness and typicality, dissociations of atypically represented praxis from typical left-lateralized language were common (~20% of cases), whereas the inverse dissociations of atypically represented language from typical left-lateralized praxis were very rare (in ~2.5% of all cases). The consequences of the existence of such different phenotypes for theoretical accounts of manual praxis, and its links to language and handedness are modeled and discussed.
虽然利普曼是最早考虑熟练的手工动作（实践）与自由记忆任务中的语言之间关系的研究人员之一，但他的主要关注点是实践的组织与左半球优势之间的关系。随后，尝试将他的失用症模型应用于他研究的所有病例——包括他的第一位患者，一位被视为例外的“非纯粹右撇子”——导致实践用手问题仍未解决。现代神经心理学和最近的神经影像学证据表明，实践与语言的关联比用手与这两种功能中的任何一种的关联更为密切，或者更侧重于它们的分离。然而，目前神经影像学和统计学的发展使我们能够克服早期实践语言用手联系研究的局限性，并更好地量化它们的相互关系。我们使用功能磁共振成像（fMRI）研究了工具使用模仿和亚言语单词生成，共 125 名参与者，包括右利手（N=52）、混合利手（N=31）和左利手（N=42）。我们使用体素计数和信号强度在两个关键细胞构筑地图和 180 个人类大脑皮层的多模态分区中计算了侧化指数，并进一步分析了最相关的感兴趣区域及其网络。我们发现，所有用手群体（RH=25.0%，MH=22.6%；LH=45.2%）中都存在实践组织异常，而且这种异常比语言组织异常（RH=3.8%；MH=6.5%；LH=26.2%）常见约两倍半，这取决于 ROI 选择/LI 计算方法。尽管实践与语言之间存在很强的关联，无论用手和典型性如何，异常表现的实践与典型的左侧化语言之间的分离是常见的（约 20%的病例），而异常表现的语言与典型的左侧化实践之间的逆向分离则非常罕见（在所有病例中约 2.5%）。对于手工实践的理论解释及其与语言和用手的联系，存在这种不同表型的后果进行了建模和讨论。
