A maturational frequency discrimination deficit may explain developmental language disorder.

Area of Science:

• Neuroscience
• Computational Auditory Neuroscience
• Developmental Psychology

Background:

• Auditory perceptual deficits are common in children with developmental language disorder (DLD), but their exact nature and impact are debated.
• Existing theories lack a clear explanation for how early auditory processing issues contribute to DLD's speech and language problems.

Purpose of the Study:

• To investigate the hypothesis that disrupted cochlear maturation leads to auditory processing deficits, impacting speech and language development.
• To model the cascading effects of impaired auditory frequency sensitivity on language acquisition and cognitive functions.

Main Methods:

• Computational simulations using deep convolutional neural networks trained on naturalistic speech.
• Biologically accurate inner ear models simulating human cochlea function with varied maturation rates.
• Analysis of network outputs to replicate linguistic and neurophysiological characteristics of DLD.

Main Results:

• Delayed cochlear maturation in models replicated key features of DLD, including delayed language acquisition and reduced word recognition.
• Simulations showed difficulties in word finding, fuzzy speech encodings, and signatures of immature neural optimization.
• Emergent working memory and attentional deficits were observed, suggesting cascading cognitive impacts.

Conclusions:

• A primary deficit in auditory frequency discrimination due to delayed cochlear maturation can significantly impair early language development.
• This model provides a framework for understanding auditory processing deficits in DLD and generates testable hypotheses for future research.