Exploring Allophonic Perception Through Cortical Electroencephalography in Adults with Dyslexia

Objective: Previous studies have expressed that individuals with dyslexia may be hypersensitive to stimuli when compared to typical individuals, creating the neural noise hypothesis. This study uses electroencephalogram (EEG) to look at participants' mismatch negativity (MMN) response to the distinctive English phoneme /æ/ and an allophone of the phoneme /æ/, measuring their reaction to the variation between these two sounds. Methods: Twenty-two adults, fourteen with dyslexia and 8 controls partook in an auditory oddball EEG experiment measuring MMN with the amplitudes and latencies being collected. Results: Five participants demonstrated a large MMN response, four of which were in the dyslexic group. These participants’ results indicate an increased sensitivity to phonetic differences. Significance: Understanding how some individuals with dyslexia process phonetic differences may be key to comprehending how a dyslexic subtype takes in auditory information.