Semantic processing in children with cochlear implants: Evidence from event-related potentials

Area of Science:

• Neuroscience
• Developmental Psychology
• Speech and Hearing Sciences

Background:

• Children with cochlear implants (CIs) often exhibit deficits in spoken language comprehension compared to typically hearing peers.
• The N400 effect, an electrophysiological measure, reflects the brain's processing of semantic information and lexical incongruence.

Purpose of the Study:

• To investigate the neural processing of lexical-semantic incongruence in children with CIs using event-related potentials (ERPs).
• To compare the N400 effect between children with CIs and typically hearing children.
• To explore the relationship between electrophysiological measures and behavioral assessments of spoken language.

Main Methods:

• Event-related potentials (ERPs) were recorded from 12 children with CIs (ages 6-9) and 30 typically hearing children during a spoken word-picture matching task.
• Independent samples t tests and ANOVA were used to compare N400 effect parameters (amplitude, latency) between the CI and typically hearing groups.
• Correlational analyses examined the link between ERP measures and behavioral scores for spoken language comprehension within each group.

Main Results:

• Both children with CIs and typically hearing children elicited an N400 effect, with no significant differences in amplitude or latency between the groups.
• Children with CIs demonstrated significantly lower scores on behavioral measures of spoken word and sentence comprehension.
• No significant correlations were found between ERP measures and behavioral outcomes in the CI group, though a trend was observed in the typically hearing group.

Conclusions:

• Children with CIs appear to process lexical-semantic incongruence at a neural level comparable to typically hearing peers.
• The N400 effect does not fully capture the complexities underlying spoken language difficulties in children with CIs.
• Factors beyond semantic processing, not assessed by the N400, likely contribute to the observed language comprehension challenges in this population.