GRADE-RELATED CHANGES IN EVENT-RELATED POTENTIALS (ERPS) IN PRIMARY-SCHOOL CHILDREN - DIFFERENCES BETWEEN 2 READING TASKS

Event-related potentials (ERPs) were recorded from the left and right temporal and parietal sites during word reading in a group of children who were followed over three consecutive years, starting at Grade 1. The first task required the child to read repeatedly presented words; the second task consisted of a series of different words, with each wo rd being presented only once. All ERP components showed changes in amp litude as a function of grade: P240, N530, the parietal N150, and SW a ll decreased, whereas the temporal N360 and SW both increased. In addi tion, SW changed from no asymmetry to larger positivity over the right site, whereas N360 changed from symmetric amplitudes to larger amplit udes over the left hemisphere with grade. Single word presentations we re associated with smaller SW activity and larger N530 and N360 amplit udes than were repeated word presentations. It was also found that pro ficient readers showed larger SW and N360 asymmetries and shorter voca l response times than did less proficient readers. In addition, a posi tive relationship was found between reading performance and ERP amplit udes over the left temporal hemisphere at Grades 2 and 3, particularly in the single word reading task. The results are discussed in terms o f age-related changes in right and left hemisphere functions involved in learning to read.