Age-Dependent Auditory Plasticity: Critical Periods in Subcortical and Cortical Encoding

Area of Science:

• Neuroscience
• Auditory System Research
• Developmental Neuroscience

Background:

• Auditory plasticity is the auditory system's ability to reorganize based on experience, crucial for neural development.
• Understanding age-dependent plasticity, especially critical and sensitive periods, is vital for auditory system development.
• Existing models may oversimplify the distinct maturation timelines of the brainstem and cortex.

Purpose of the Study:

• To synthesize evidence on age-dependent auditory plasticity across subcortical and cortical levels.
• To introduce the Graded Windows Model (GWM) as a framework for understanding auditory plasticity.
• To provide clinical recommendations for intervention timing based on evidence levels.

Main Methods:

• A systematic scoping review following PRISMA-ScR guidelines.
• Searched PubMed/MEDLINE, Scopus, and Web of Science databases (1963-2025).
• Thematic synthesis of data from 78 included studies after screening 2,437 records.

Main Results:

• Identified methodological limitations in current research.
• Proposed the Graded Windows Model (GWM), suggesting overlapping, interacting plasticity windows along the auditory neuraxis.
• Distinguished human and animal evidence, challenging the simple dichotomy of early brainstem and later cortical maturation.

Conclusions:

• Auditory plasticity involves hierarchically organized, graded windows, not a simple early vs. late maturation process.
• The GWM offers a more nuanced framework for understanding auditory plasticity across the lifespan.
• This framework can guide optimal intervention timing to prevent maladaptive plasticity.