Krishnan Ananthanarayan, Gandour Jackson T, Xu Yi, Suresh Chandan H
Department of Speech Language Hearing Sciences, Purdue University, West Lafayette, IN USA.
Department of Speech, Hearing and Phonetic Sciences, University College London, UK.
J Neurolinguistics. 2017 Feb;41:38-49. doi: 10.1016/j.jneuroling.2016.09.005. Epub 2016 Sep 16.
There remains a gap in our knowledge base about neural representation of pitch attributes that occur between onset and offset of dynamic, curvilinear pitch contours. The aim is to evaluate how language experience shapes processing of pitch contours as reflected in the amplitude of cortical pitch-specific response components. Responses were elicited from three nonspeech, bidirectional (falling-rising) pitch contours representative of Mandarin Tone 2 varying in location of the turning point with fixed onset and offset. At the frontocentral Fz electrode site, Na-Pb and Pb-Nb amplitude of the Chinese group was larger than the English group for pitch contours exhibiting later location of the turning point relative to the one with the earliest location. Chinese listeners' amplitude was also greater than that of English in response to those same pitch contours with later turning points. At lateral temporal sites (T7/T8), Na-Pb amplitude was larger in Chinese listeners relative to English over the right temporal site. In addition, Pb-Nb amplitude of the Chinese group showed a rightward asymmetry. The pitch contour with its turning point located about halfway of total duration evoked a rightward asymmetry regardless of group. These findings suggest that neural mechanisms processing pitch in the right auditory cortex reflect experience-dependent modulation of sensitivity to weighted integration of changes in acceleration rates of rising and falling sections and the location of the turning point.
在我们的知识库中,关于动态、曲线音高轮廓起始和结束之间出现的音高属性的神经表征仍存在差距。目的是评估语言经验如何塑造音高轮廓的处理,这在皮层音高特异性反应成分的幅度中有所体现。从三个非语音、双向(降-升)音高轮廓引发反应,这些轮廓代表普通话第二声,转折点位置不同,但起始和结束固定。在额中央Fz电极部位,对于转折点位置相对于最早位置更靠后的音高轮廓,中国组的Na-Pb和Pb-Nb幅度大于英语组。中国听众对那些转折点更靠后的相同音高轮廓的反应幅度也大于英语听众。在颞叶外侧部位(T7/T8),相对于英语听众,中国听众在右侧颞叶部位的Na-Pb幅度更大。此外,中国组的Pb-Nb幅度表现出向右不对称。转折点位于总时长大约一半位置的音高轮廓,无论组别如何,都会引发向右不对称。这些发现表明,右侧听觉皮层中处理音高的神经机制反映了对上升和下降部分加速度变化的加权整合以及转折点位置的敏感度的经验依赖性调制。