Electroencephalographic and brain stem evoked responses from learning‐disabled and control children

Abstract

This study examined both electroencephalography (EEG) and brain stem evoked responses (BSERs) as indices of cortical dysfunction in children who experience learning disabilities (LD). Fifteen 9‐ to 12‐year‐olds from self‐contained LD classrooms were compared with 15 control children of the same age‐range for eyes‐open and eyes‐closed spontaneous EEG and for lateral symmetry of click‐elicited BSERs. Spontaneous EEG with eyes closed showed the largest between‐group differences over the bilateral temporal sites, where the LD group demonstrated a relative depression of delta and theta frequency bands and a relative increase in alpha. Control children, however, exhibited a more orderly progression or rate of maturation in EEG development compared to LD children. Neither differences in latencies of BSER peaks, I, III, and V, nor lateral asymmetry in BSERs were found between the diagnostic groups. Similar to the findings for EEGs, control children exhibited a more systematic increase in BSER peak latencies as a function of age. The lack of developmental changes for the LD group with the electrophysiological indices may be associated with atypical brain electrical activity and subsequent performance on cognitive‐related tasks.