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.

在发展性语言障碍（DLD）中，学习理解和用口语表达自己的能力受到损害，但其原因仍不清楚。使用毫秒级脑磁图记录与机器学习模型相结合，我们研究了这种干扰的可能神经基础是否在于语音的皮层跟踪不良。刺激是常见的芬兰语单词（例如，狗、汽车、锤子）和具有相应含义的声音（例如，狗吠、汽车引擎、锤击）。在 10-15 岁的 DLD 儿童（10 名男孩和 7 名女孩）和典型发育 (TD) 对照儿童（14 名男孩和 3 名女孩）中，对口语单词的皮层激活最好建模为时间锁定的展开模型。声音和皮质激活之间的语音输入延迟约为 100 毫秒。根据双侧颞区的时间锁定大脑反应，可以非常成功地解码口语单词的幅度包络（幅度变化）和频谱图（详细的随时间变化的频谱内容），但其他声音则不然。根据皮质反应，模型可以以约 75-85% 的准确度判断向参与者呈现的两种声音中的哪一种。然而，与 TD 儿童相比，DLD 儿童的振幅包络信息的皮质表征在较长潜伏期（约 200–300 ms 滞后）下较差。我们将这种效应解释为反映了短期记忆中声音-语音信息的保留较差。这种受损的跟踪可能会影响单词的处理和学习以及连续语音。目前的结果为 DLD 中语言理解和习得的问题提供了解释。