Goldenberg Georg, Hermsdörfer Joachim, Glindemann Ralf, Rorden Chris, Karnath Hans-Otto
Neuropsychological Department, Bogenhausen Hospital, D 81925 Munich, Germany.
Cereb Cortex. 2007 Dec;17(12):2769-76. doi: 10.1093/cercor/bhm004. Epub 2007 Mar 5.
Pantomime of tool use is a frequently used test for apraxia. For basic cognitive neuroscience, pantomime of tool use is of interest because it constitutes a link between instrumental and communicative manual actions. We used lesion subtraction analysis to determine the locations specifically associated with defective pantomime of tool use in patients with left-brain damage and aphasia. Subtraction of lesions of patients with normal pantomime from those with defective pantomime yielded a maximum difference in the inferior frontal gyrus and adjacent portions of the insula and precentral gyrus. This result remained essentially the same when possible confounding influences of impaired language comprehension and of lesion size were controlled by selecting patients equated on these measures and when only patients with preserved imitation of gestures were considered. By contrast, parietal lesions did not have a specific impact on pantomime. We speculate that the vulnerability of pantomime to lesions of left inferior frontal cortex is due to the high demands on selection of a very restrained range of features out of the many features that may come to mind when imagining the actual use of the tool.
工具使用模仿是一种常用于失用症测试的方法。对于基础认知神经科学而言，工具使用模仿具有重要意义，因为它构成了工具性手部动作与交流性手部动作之间的联系。我们采用病变减法分析来确定与左脑损伤及失语症患者工具使用模仿缺陷具体相关的脑区位置。用工具使用模仿正常患者的病变区域减去模仿缺陷患者的病变区域，结果显示在额下回以及岛叶和中央前回的相邻部分差异最大。当通过选择在语言理解受损程度和病变大小这些指标上相当的患者来控制可能存在的混淆影响时，以及当仅考虑手势模仿能力保留的患者时，这一结果基本保持不变。相比之下，顶叶病变对模仿没有特定影响。我们推测，工具使用模仿对左下额叶皮质病变的易损性是由于在想象工具实际使用时，需要从众多可能想到的特征中挑选出非常有限的一系列特征，这对选择能力要求很高。
