FONO SENSE: a technological resource for recording the auditory N400 component

This study aimed to develop a tool for phonological auditory electrophysiological assessment, focusing on the N400 component of Event-Related Potentials in adults and children with and without dyslexia. The cross-sectional analytical research, approved by the ethics committee (protocol n° 4.565.753), included 25 participants divided into three groups: 10 children with dyslexia (EG), 5 children without dyslexia (CG-s), and 10 adults without learning disorders (CG-a). The study was conducted in two phases. The first phase involved developing a mobile application with Congruent and Incongruent phonological tasks using words and non-words to assess reading, letter-sound relationships, syntactic-semantic integration, and lexical memory. In the second phase, participants performed auditory-linguistic tasks with acoustic stimuli (/ba/and/da/), combined with the app tasks, while the N400 potential was recorded using the Biologic's Evoked Potential System (EP) with binaural stimulation in an oddball paradigm. The results showed a significant difference in latency between EG and CG-a for the incongruent task, with EG displaying delayed latency. Only CG-a exhibited a significant latency reduction in the incongruent task. No significant differences in amplitude were observed between groups or factors. In conclusion, the application effectively elicited the N400 potential in all groups, demonstrating shorter latencies in adults compared to children, both with and without dyslexia.