Impaired Cortical Tracking of Speech in Children with Developmental Language Disorder

Area of Science:

• Neuroscience
• Developmental Psychology
• Linguistics

Background:

• Developmental language disorder (DLD) is characterized by impaired spoken language comprehension and expression.
• The underlying neural mechanisms contributing to DLD remain largely unknown.
• Investigating cortical tracking of speech offers a potential avenue to understand DLD's basis.

Purpose of the Study:

• To determine if impaired cortical tracking of speech underlies developmental language disorder (DLD).
• To compare neural speech tracking between children with DLD and typically developing (TD) children.
• To explore the relationship between speech tracking deficits and language acquisition challenges in DLD.

Main Methods:

• Utilized millisecond-scale magnetoencephalography (MEG) recordings.
• Employed machine learning models to decode brain responses to auditory stimuli.
• Compared brain activity in response to spoken words and non-speech sounds in children with DLD and TD controls.

Main Results:

• Cortical responses to spoken words were time-locked with a ~100 ms latency in both groups.
• Speech amplitude envelope and spectrogram information were decoded with 75-85% accuracy from brain activity.
• Children with DLD exhibited poorer cortical representation of amplitude envelope information at longer latencies (~200-300 ms) compared to TD children.

Conclusions:

• Poorer cortical tracking of speech, particularly at later latencies, suggests impaired retention of acoustic-phonetic information in short-term memory for children with DLD.
• This neural deficit may explain difficulties in word processing, learning, and continuous speech comprehension in DLD.
• The findings provide a potential neural explanation for language acquisition and comprehension impairments in developmental language disorder.