Gender Differences in Reading in School-Aged Children: An Early ERP Study

Language lateralization in the auditory modality occurs relatively early in pre-school children. Instead, lateralization of linguistic processes involved in reading develops more slowly in parallel with learning to read. In adults there is limited evidence that language lateralization differs across genders. With the present experiment we aimed at demonstrating that gender-related lateralization difference begins earlier, in school-aged children, with characteristics similar to those observed in adults. To this aim, 14 boys and 14 girls aged 10 participated in a linguistic experiment including Orthographic, Phonological, and Semantic tasks. Early potentials evoked by single-word reading revealed a posterior negative wave peaking at 230 msec, corresponding to the N150-Recognition Potential, and a more anterior and late N350. Boys showed a bilateral N150 in all tasks, whereas girls' N150 was right lateralized in both the Phonological and the Orthographic tasks. In the later interval (300-400 msec) boys' N350 was left lateralized over anterior sites during the Phonological task and girls exhibited bilateral activation in all tasks. Results support the hypothesis that a reduced left language lateralization can be functionally detected in females since the first years of development of reading skills.