The development of lateral event-related potentials (ERPs) related to word naming: a four year longitudinal study.

Event-related potentials (ERPs) were recorded from the left and right temporal and parietal sites during a word naming task. Subjects were a group of children that were followed over four consecutive years starting at Kindergarten. ERP waveforms contained a sequence of positive and negative components (N150, P240, N360, N530 and SW). All components, except N150, showed changes in amplitude as a function of age, whereas SW, N360 and N150 also changed in hemispheric distribution. In addition, a relationship was found between reading performance and ERP amplitudes over the right parietal hemisphere in young children, and over the left temporal hemisphere in older children. Proficient readers showed larger (more negative) parietal N530 amplitudes than less proficient readers, especially when stimuli were degraded words. The results are discussed in terms of age-related changes in right and left hemisphere functions involved in early and advanced stages of reading, that might possibly be related to visual word recognition.