A new study brings neural-level evidence that the continuous variation in natural speech makes the discrimination of phonemes challenging for adults suffering from developmental reading-deficit dyslexia. This may compromise the learning of native language phonemes already at an early age for infants at familial risk for dyslexia.
The participants listened to a stream of Finnish speech sounds at various pitch levels passively, with their attention directed away from the stimulation, and actively, by pressing a response button when detecting a change in the speech sounds. Auditory event-related potentials differed between the two groups in both conditions. Dyslexic participants were also less accurate in detecting the changes.