Wang Natalie Yu-Hsien, Chiang Chun-Han, Wang Hsiao-Lan Sharon, Tsao Yu
Department of Audiology and Speech-Language Pathology, Asia University, Taichung, Taiwan.
Department of Special Education, National Pingtung University, Pingtung, Taiwan.
Front Psychol. 2020 Aug 11;11:1649. doi: 10.3389/fpsyg.2020.01649. eCollection 2020.
Chinese lexical tones determine word meaning and are crucial in reading development. Reduced tone awareness is widely reported in children with reading difficulties (RD). Lexical-tone processing requires sensitivity to frequency-modulated sound changes. The present study investigates whether reduced tone awareness in children with RD is reflected in basic auditory processing and the level at which the breakdown occurs. Magnetoencephalographic techniques and an oddball paradigm were used to elicit auditory-related neural responses. Five frequency sweep conditions were established to mirror the frequency fluctuation in Chinese lexical tones, including one standard (level) sweep and four deviant sweeps (fast-up, fast-down, slow-up, and slow-down). A total of 14 Chinese-speaking children aged 9-12 years with RD and 13 age-matched typically developing children were recruited. The participants completed a magnetoencephalographic data acquisition session, during which they watched a silent cartoon and the auditory stimuli were presented in a pseudorandomized order. The results revealed that the significant between-group difference was caused by differences in the level of auditory sensory processing, reflected by the P1m component elicited by the slow-up frequency sweep. This finding indicated that auditory sensory processing was affected by both the duration and the direction of a frequency sweep. Sensitivity to changes in duration and frequency is crucial for the processing of suprasegmental features. Therefore, this sensory deficit might be associated with difficulties discriminating two tones with an upward frequency contour in Chinese.
汉语声调决定词义，对阅读发展至关重要。阅读障碍（RD）儿童中普遍存在声调感知能力下降的情况。词汇声调处理需要对调频声音变化有敏感度。本研究调查了RD儿童声调感知能力下降是否体现在基本听觉处理上以及这种障碍发生在何种水平。采用脑磁图技术和Oddball范式来引发与听觉相关的神经反应。设定了五种频率扫描条件以反映汉语词汇声调中的频率波动，包括一种标准（水平）扫描和四种偏差扫描（快速上升、快速下降、缓慢上升和缓慢下降）。共招募了14名9至12岁的汉语RD儿童和13名年龄匹配的发育正常儿童。参与者完成了一次脑磁图数据采集过程，在此期间他们观看无声卡通片，听觉刺激以伪随机顺序呈现。结果显示，组间显著差异是由听觉感觉处理水平的差异引起的，这种差异由缓慢上升频率扫描引发的P1m成分反映出来。这一发现表明，听觉感觉处理受到频率扫描的持续时间和方向的影响。对持续时间和频率变化的敏感度对于超音段特征的处理至关重要。因此，这种感觉缺陷可能与辨别汉语中两个具有上升频率轮廓的声调存在困难有关。
