PDF(Pubmed)
Abstract：
In developmental language disorder (DLD), learning to comprehend and express oneself with spoken language is impaired, but the reason for this remains unknown. Using millisecond-scale magnetoencephalography recordings combined with machine learning models, we investigated whether the possible neural basis of this disruption lies in poor cortical tracking of speech. The stimuli were common spoken Finnish words (e.g., dog, car, hammer) and sounds with corresponding meanings (e.g., dog bark, car engine, hammering). In both children with DLD (10 boys and 7 girls) and typically developing (TD) control children (14 boys and 3 girls), aged 10-15 years, the cortical activation to spoken words was best modeled as time-locked to the unfolding speech input at ∼100 ms latency between sound and cortical activation. Amplitude envelope (amplitude changes) and spectrogram (detailed time-varying spectral content) of the spoken words, but not other sounds, were very successfully decoded based on time-locked brain responses in bilateral temporal areas; based on the cortical responses, the models could tell at ∼75-85% accuracy which of the two sounds had been presented to the participant. However, the cortical representation of the amplitude envelope information was poorer in children with DLD compared with TD children at longer latencies (at ∼200-300 ms lag). We interpret this effect as reflecting poorer retention of acoustic-phonetic information in short-term memory. This impaired tracking could potentially affect the processing and learning of words as well as continuous speech. The present results offer an explanation for the problems in language comprehension and acquisition in DLD.
摘要：
在发育性语言障碍（DLD）中，用口语理解和表达自己的学习受到损害，但原因仍然未知。使用毫秒级脑磁图（MEG）记录与机器学习模型相结合，我们调查了这种干扰的可能神经基础是否在于语音皮层跟踪不良。刺激是常见的口语(例如，\'狗\',\'汽车\',\'hammer\')和具有相应含义的声音(例如，狗叫声,汽车发动机,锤击）。在患有DLD的儿童（10个男孩和7个女孩）和典型的发育（TD）控制儿童（14个男孩和3个女孩）中，10-15岁,对口语单词的皮层激活最好建模为在声音和皮层激活之间的~100ms潜伏期锁定到展开的语音输入。语音的振幅包络（振幅变化）和频谱图（详细的随时间变化的频谱内容），但不是其他声音，根据双侧颞区的时间锁定的大脑反应非常成功地解码；根据皮质反应，这些模型可以分辨75%-85%的准确率，两种声音中的哪一种已经呈现给参与者。然而,与延迟时间较长(~200-300ms滞后)的TD儿童相比,DLD儿童的振幅包络信息的皮质表现较差.我们将这种影响解释为反映了短期记忆中声学语音信息的保留较差。这种受损的跟踪可能会影响单词以及连续语音的处理和学习。本研究结果为DLD中的语言理解和习得问题提供了解释。重要性陈述用脑磁图（MEG）研究了发育性语言障碍（DLD）中言语处理受损的神经基础，自然的口语和声音，和最先进的机器学习模型。语音的皮质跟踪在初始阶段是正常的，但在音节级潜伏期受损，反映了在整个单词中保持传入语音的皮层记忆表示形式的问题。这为DLD中识别单词和学习新单词的问题提供了解释。
