Correlation between brainstem and cortical auditory processes in normal and language-impaired children.
A functional relationship between brainstem and cortical auditory processing was shown to be abnormal in children with language-based learning problems (LP). Auditory evoked potentials were used to investigate brainstem and cortical responses to the speech sound /da/. The duration of the wave V-V(n) complex of the auditory brainstem response was studied, as was the effect of noise on correlations between cortical responses to repeated stimuli. The group of LP children (n = 11) demonstrated abnormal encoding of speech sounds on both individual measures of brainstem and cortical processing; prolonged wave V-V(n) duration and pronounced susceptibility of cortical correlations to degradation by noise were both interpreted as reflecting diminished synchrony of response generator mechanisms. Furthermore, the LP group as a whole failed to demonstrate a relationship between brainstem and cortical measures that was demonstrated to be quite strong across all normal children (NL, n = 9). However, a subset of roughly three-quarters of the LP children appeared to demonstrate the normal relationship between brainstem and cortical processing, suggesting that they share a common functional connection with NL children. This relatively normal relationship between brainstem and cortical auditory processing in most LP children, as well as the exceptions to this relationship reflected by a smaller portion of LP children, may delineate different subclasses of auditory-language-based learning problems. This suggests the potential for use of these measures as diagnostic tools.
Wible
Brad
B
Department of Psychology, University of Oregon, Eugene, Oregon, USA.
Nicol
Trent
T
Kraus
Nina
N
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D001933:Brain Stem / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D005072:Evoked Potentials, Auditory; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted