Centre for Neuroscience in Education, University of Cambridge, Cambridge, UK.
J Cogn Neurosci. 2011 Feb;23(2):325-37. doi: 10.1162/jocn.2010.21453. Epub 2010 Feb 10.
Studies in sensory neuroscience reveal the critical importance of accurate sensory perception for cognitive development. There is considerable debate concerning the possible sensory correlates of phonological processing, the primary cognitive risk factor for developmental dyslexia. Across languages, children with dyslexia have a specific difficulty with the neural representation of the phonological structure of speech. The identification of a robust sensory marker of phonological difficulties would enable early identification of risk for developmental dyslexia and early targeted intervention. Here, we explore whether phonological processing difficulties are associated with difficulties in processing acoustic cues to speech rhythm. Speech rhythm is used across languages by infants to segment the speech stream into words and syllables. Early difficulties in perceiving auditory sensory cues to speech rhythm and prosody could lead developmentally to impairments in phonology. We compared matched samples of children with and without dyslexia, learning three very different spoken and written languages, English, Spanish, and Chinese. The key sensory cue measured was rate of onset of the amplitude envelope (rise time), known to be critical for the rhythmic timing of speech. Despite phonological and orthographic differences, for each language, rise time sensitivity was a significant predictor of phonological awareness, and rise time was the only consistent predictor of reading acquisition. The data support a language-universal theory of the neural basis of developmental dyslexia on the basis of rhythmic perception and syllable segmentation. They also suggest that novel remediation strategies on the basis of rhythm and music may offer benefits for phonological and linguistic development.
研究感官神经科学揭示了准确的感官知觉对认知发展的至关重要性。关于语音处理的可能感官相关性存在相当大的争议，语音处理是发展性阅读障碍的主要认知风险因素。在各种语言中，阅读障碍儿童在言语语音结构的神经表示方面存在特定的困难。识别语音困难的稳健感觉标记物将能够早期识别发展性阅读障碍的风险，并进行早期有针对性的干预。在这里，我们探讨语音处理困难是否与处理言语节奏的听觉线索的困难有关。言语节奏被婴儿用于将言语流分割成语词和音节。早期感知听觉言语节奏和韵律的困难可能会导致语音发展受损。我们比较了具有和不具有阅读障碍的儿童的匹配样本，他们学习三种非常不同的口语和书面语言，英语、西班牙语和中文。测量的关键感觉线索是幅度包络的起始率（上升时间），已知其对言语的节奏定时至关重要。尽管存在语音和正字法差异，但对于每种语言，上升时间敏感性都是语音意识的重要预测因素，并且上升时间是阅读获得的唯一一致预测因素。这些数据支持了基于节奏感知和音节分割的发展性阅读障碍的神经基础的普遍语言理论。它们还表明，基于节奏和音乐的新矫正策略可能对语音和语言发展有益。
