Event-related potential correlates of primed and unprimed words in children co-morbid for disruptive behaviour disorders and academic delay.

Children with disruptive behaviour disorders and academic delay (DD-AD) were compared to children with disruptive behaviour disorders only (DD) and normal control children with no psychiatric disturbance or academic delay (NO) with respect to scalp-recorded event-related electrical potentials (ERPs) elicited by semantically primed and unprimed words. Primed words were preceded by spoken words having a related meaning, while unprimed words were preceded by nonassociated spoken words. For normal controls, the unprimed words elicited greater N400 amplitudes at frontal-central recording sites than primed words. Primed vs. unprimed N400 differences were not evident at frontal sites in DD and the DD-AD group failed to exhibit differences in primed vs. unprimed N400 amplitudes at either frontal, central or parietal sites. These findings suggest that DD-AD children may represent a unique neuroelectric subgroup of learning disabilities.