Dynamic behavioral and neural correlates of letter-speech sound learning in typical and dyslexic readers.

Difficulties in forming letter-speech sound associations may constitute a challenge for individuals with dyslexia. However, the learning trajectories of these associations remain poorly understood. This EEG study examined behavioral and neural changes while 31 typical and 31 dyslexic adult readers learned to map six novel symbols to Dutch spoken syllables with either high or low phonological similarity. Both groups demonstrated successful learning with learning-related ERP changes over frontotemporal, temporoparietal, and occipitoparietal regions. Phonologically similar vs. dissimilar pairs showed lower accuracy, slower reaction times, and reduced ERP responses, with earlier frontotemporal effects in dyslexic vs. typical readers (block 2 vs. blocks 3-4). As for learning outcomes, both groups showed temporoparietal (mis)matching responses in the last block. Dyslexic readers had lower post-training symbol reading scores, which correlated with their reading and phonological skills. Our findings indicate comparable learning during initial symbol-sound association in dyslexic readers, but difficulties applying novel associations during reading.