BCN-Neuroimaging Center, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 2, PO Box 196, 9700 AD Groningen, the Netherlands.
BMC Neurosci. 2010 Aug 10;11:93. doi: 10.1186/1471-2202-11-93.
The right hemisphere may play an important role in paralinguistic features such as the emotional melody in speech. The extent of this involvement however is unclear. Imaging studies have shown involvement of both left and right inferior frontal gyri in emotional prosody perception. The present pilot study examined whether these brain areas are critically involved in the processing of emotional prosody and of semantics in 9 healthy subjects. Repetitive transcranial magnetic stimulation was used with a coil centred over left and right inferior frontal gyri, as localized by neuronavigation based on the subject's MRI. A sham condition was included. An online-TMS approach was applied; an emotional language task was completed during stimulation. This computerized task consisted of sentences pronounced by actors. In the semantics condition an emotion (fear, anger or neutral) was expressed in the content pronounced with a neutral intonation. In the prosody condition the emotion was expressed in the intonation, while the content was neutral.
Reaction times on the emotional prosody task condition were significantly longer after rTMS over both the right and the left inferior frontal gyrus as compared to sham stimulation and after controlling for learning effects associated with order of condition. When taking all emotions together, there was no difference in effect on reaction times between the right and left stimulation. For the emotion Fear, reaction times were significantly longer after stimulating the left inferior frontal gyrus as compared to the right inferior frontal gyrus. Reaction times in the semantics task condition were not significantly different between the three TMS conditions.
The data indicate a critical involvement of both the right and the left inferior frontal gyrus in emotional prosody perception. The findings of this pilot study need replication. Future studies should include more subjects and examine whether the left and right inferior frontal gyrus play a differential role and complement each other, e.g. in the integrated processing of linguistic and prosodic aspects of speech, respectively.
右半球可能在言语的非语言特征（如情感旋律）中发挥重要作用。然而，这种参与的程度尚不清楚。影像学研究表明，左、右额下回均参与情感韵律感知。本研究旨在探讨 9 名健康受试者的这些脑区是否对情绪韵律和语义的处理具有关键作用。采用经颅重复磁刺激（rTMS），线圈置于左、右额下回正中，基于受试者的 MRI 进行神经导航定位。同时纳入假刺激条件。采用在线-TMS 方法，在刺激过程中完成情绪语言任务。该计算机任务由演员朗读的句子组成。在语义条件下，用中性语调表达内容中的情绪（恐惧、愤怒或中性）。在韵律条件下，用语调表达情绪，而内容为中性。
与假刺激相比，rTMS 刺激右、左额下回后，情绪韵律任务的反应时间显著延长，且控制条件顺序相关的学习效应后，结果仍具有统计学意义。当综合考虑所有情绪时，左右刺激对反应时间的影响无差异。对于恐惧情绪，刺激左额下回后反应时间明显长于刺激右额下回。在语义任务条件下，三种 TMS 条件之间的反应时间无显著差异。
数据表明，左右额下回均对情绪韵律感知具有关键作用。该初步研究结果需要进一步验证。未来的研究应包括更多的受试者，并进一步研究左、右额下回是否在语言和韵律方面分别发挥不同作用并相互补充，例如分别在言语的语言和韵律方面的综合处理中。
