Cortical responses of infants with and without a genetic risk for dyslexia: II. Group effects.

Infants born to families with a background of developmental dyslexia have an increased risk of becoming dyslexic. In our previous study no major group or stimulus effects in the event-related potentials (ERPs) of at-risk and control infants were found until the age of 6 months. However, in the current study, when we made the stimulus presentation rate slower, the ERPs to the short deviant /ka/ were different from those to the long standard /kaa/ stimulus already in newborns. In addition, clear group differences in the ERPs were found. The results demonstrate that infants born with a high familial risk for dyslexia process speech/auditory stimulus durations differently from control infants at birth.