Abnormal brain responses to sounds in children with language and reading impairment

Children with specific language impairment (SLI; n = 19), children with specific reading disability (SRD; n = 55) and controls (n = 36) were tested for their passive N1-P2 responses to tones, rapid tones, vowels, and consonant-vowels. Thirty-eight per cent of children with SLI or children with SRD had abnormal passive N1-P2 responses to sounds in general rather than to tones, rapid tones, vowels, or consonant-vowels specifically, and these abnormal N1-P2 responses were significantly "flatter" (i.e., less steep) than normal passive auditory N1-P2 responses. The subgroup of children with SLI or SRD with flatter N1-P2 responses to sounds did not have abnormal passive N1-P2 responses to visual stimuli. However, they all had poor nonword reading. A subgroup of these poor nonword readers also had poor nonword repetition. These results support the idea that impaired auditory processing is one of a number of causal risk factors for both SLI and SRD.