Auditory evoked responses to frequency-modulated tones in children with specific language impairment.

Averaged cortically evoked potentials to frequency-modulated tones (+/- 100 Hz around a center frequency of 1 kHz) were obtained from 12 children with SLI and 12 age-matched children who were normal language learners. It was hypothesized, based on Stefanatos, Green, and Ratcliff (1989), that the children with receptive and expressive specific language impairment (SLI) would show very small or no measurable averaged response amplitudes. Also, it was predicted that children who were normal language learners would show large response amplitudes that were both significantly greater than those obtained during a stimulus control condition and greater than those obtained from the children with SLI. The prediction concerning children with SLI proved incorrect. The responses of the children with SLI were no different from those obtained from the normal language learners, and responses from both groups were significantly greater than those obtained in the control condition. These results indicate that, with respect to neural systems involved with selective response to auditory frequency shifts of approximately 100 Hz and occurring over 250 msec, children with SLI are not different from children who are normal language learners.