Non-verbal skills in auditory word processing: Implications for typical and dyslexic readers

Abstract

Dyslexia is characterized by poor phonological skills and atypical neural responses to text and speech stimuli, while non-verbal intelligence remains unaffected. However, the impact of non-verbal intelligence on language-evoked neural responses in dyslexia is underexplored. This study examines non-verbal intelligences effects on neural responses to auditory words in typical and dyslexic readers. Participants completed IQ tests, reading and phonological assessments, and underwent magnetoencephalography recordings while listening to words. Event-related brain field responses at different stages of auditory word processing (100ms, 200ms, 400ms) were analyzed in relation to non-verbal IQ scores and reading performance. Higher non-verbal IQ in typical readers yielded earlier right hemisphere perceptual responses (100ms). Dyslexic readers showed no IQ-related latency effects but those with lower non-verbal IQ displayed amplified left hemisphere response amplitudes at 100ms. These findings confirm the link between non-verbal cognitive abilities and early auditory word processing in adults, highlighting distinct effects in dyslexia and controls.