Clinical Neuropsychology Research Group, Neuropsychological Dept., Clinic Bogenhausen, Dachauer Str. 164, 80992 Munich, Germany.
Neuropsychologia. 2010 Mar;48(4):1115-24. doi: 10.1016/j.neuropsychologia.2009.12.012. Epub 2010 Jan 7.
Imitation in speech refers to the unintentional transfer of phonologically irrelevant acoustic-phonetic information of auditory input into speech motor output. Evidence for such imitation effects has been explained within the framework of episodic theories. However, it is largely unclear, which neural structures mediate speech imitation and how imitation is related with verbal repetition. Two experiments were conducted, a standard repetition task, and a transformation task requiring phonetic manipulation of the presented auditory nonword stimuli. Nonword materials varied sub-phonemically in word stress (pitch elevation magnitude; PEM) and in a parameter related to speaking style, i.e., the explicitness of final schwa-syllables (SSE). We examined speech imitation in 10 healthy participants, 10 patients with phonological impairments after left hemisphere lesions, and 11 patients with right hemisphere lesions. In repetition, significant imitation of SSE and PEM was observed in all groups of participants. In transformation, imitation occurred in healthy participants and in the patients with right hemisphere lesions, whereas no imitation was observed in the patient group with left hemisphere lesions. Voxel-based lesion-symptom mapping revealed that different areas within the left temporal plane influenced the degree of imitation of phonetic and prosodic detail in repetition.
言语模仿是指将听觉输入的与发音无关的声学语音信息无意识地转移到言语运动输出中。这种模仿效应的证据是在情节理论框架内解释的。然而，很大程度上不清楚哪些神经结构介导言语模仿，以及模仿与言语重复之间的关系。进行了两项实验，一项是标准重复任务，另一项是需要对呈现的非语音听觉刺激进行语音操作的转换任务。非语音材料在词重音（音高提升幅度；PEM）和与说话风格相关的一个参数上存在亚音位差异，即终元音-syllables 的清晰度（SSE）。我们检查了 10 名健康参与者、10 名左半球损伤后语音障碍患者和 11 名右半球损伤患者的言语模仿。在重复中，所有组的参与者都表现出对 SSE 和 PEM 的显著模仿。在转换中，健康参与者和右半球损伤患者出现了模仿，而左半球损伤患者组则没有观察到模仿。基于体素的病变-症状映射显示，左颞平面内的不同区域影响了重复中语音和韵律细节的模仿程度。
