AbstractIn an event‐related potentials study of brain–behavior relations during learning‐to‐read, girls in first grade viewed known words, unknown words, difficult words, and nonwords presented in list form. Participants were divided into low‐ability and high‐ability reading groups based on standardized test scores. During the 300‐ to 600‐ms epoch, low‐ability readers lacked a substantial N400 while high‐ability readers evidenced a large, widely distributed negativity to all word types. During the 600‐ to 1,000‐ms epoch, high‐ability readers showed effects of repetition while low‐ability readers did not. The findings indicate a less selective neurocognitive word‐processing system in children as compared to adults and suggest that the N400 may serve as an oblique index of the automaticity of lower level processing. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 146–166, 2003.