Alpha hemispheric asymmetry in children with learning disabilities and normally achieving children during story comprehension and rehearsal prior to narrative production.

Twelve children with learning disabilities attending a remedial summer clinic were compared with 12 normally achieving controls balanced for age, sex, and handedness on alpha amplitude and production of narratives. Specifically, all subjects participated in three conditions. Condition 1 was a vigilance condition, Condition 2 involved listening to a story without an ending that had to be retold, and Condition 3 was an opportunity to rehearse the story mentally and construct an appropriate ending. Alpha amplitudes were monitored during the three conditions to determine any hemispheric asymmetry or differences between groups or conditions in alpha production. The subjects' narrative productions of retelling the story with a novel ending were also analyzed using a cohesion analysis procedure. The results showed no significant differences between the groups in alpha amplitude, but there was a significant task effect with the vigilance condition, story comprehension, and rehearsal showing decreasing alpha amplitudes in both groups of subjects. Analysis of the narratives showed the group with learning disabilities to produce significantly shorter and less cohesive stories. Results are discussed in relation to other studies of hemispheric processing differences in populations with learning disabilities.