Reading skills modulate the audiovisual congruency effect in orthographic processing in children: an ERP study

Introduction Integration of written and spoken information is crucial for reading acquisition. Correspondingly, individuals with reading difficulties exhibit deficiencies in audiovisual (AV) congruency processing. The timeline of AV congruency processing in children and the influence of reading skills on this process, however, remain largely unclear. Therefore, we examined when and how reading skills modulate AV congruency processing for orthographic (words, pseudowords) and non-orthographic conditions (objects). Methods Eighty-two native German-speaking 2nd and 3rd graders completed an explicit task involving the matching of AV congruent and incongruent orthographic and non-orthographic stimuli, while EEG was recorded. Results Behaviorally, poorer reading skills were associated with lower performance and slower responses for orthographic conditions. Neurally, topographic EEG analyses revealed congruency effects emerging after 300 ms for orthographic conditions and around 200 ms for objects. ERP analyses showed that reading skills modulated the N400 incongruency effect more strongly for orthographic than non-orthographic stimuli. Discussion In summary, poorer reading skills were associated with slower AV matching and a weaker N400 incongruency effect for orthographic conditions. These findings suggest that while reading skills might not broadly affect AV congruency processing, they critically impact the AV congruency processing of orthographic information, potentially hindering struggling readers’ ability to effectively use preceding auditory information to process print.