Assessing auditory processing disorders in children with developmental dyslexia using auditory cognitive event-related potentials.

OBJECTIVES

It has been suggested that dyslexia is linked to a core cognitive deficit in phonological awareness tasks and/or in the processing of auditory stimuli. Auditory evoked potentials are a valid, objective measure of the accuracy of central auditory processing in humans. The aim of this study was to assess auditory evoked potentials in children with dyslexia.

PATIENTS AND METHODS

Sixty-six children participated in the study. A set of hearing tests and the recording of complex event-related potentials (ERPs) were performed.

RESULTS

Mixmatch negativity (MMN) and P300 waves were significantly more frequent in the healthy children (control group) than in children with dyslexia. The P300 wave was present in all subjects from the control group, the MMN wave in 92% of them. In the dyslexic group, complex ERPs were recorded roughly 33% of the time. Latencies of complex ERPs in children with dyslexia were greater than latencies in children in the control group. MMN and P300 maturation (change with age) was observed only for the control group. A wide range of MMN and P300 responses was observed across children with dyslexia.

CONCLUSION

Complex ERPs may be useful in determining the condition of audiologic functions; however, on their own they are not sufficient to recognize dyslexia because of the heterogeneity of nonspecific changes.