The N400 Effect and Reading Difficulties in Elementary School Children

Abstract

Reading difficulties are prevalent amongst children. The present study examines the differences between children with reading difficulties and children with typical reading skills on reading-language performance as well as the N400 lexicality effect. The N400 is a waveform captured by electroencephalography (EEG) when individuals engage in meaning processing. Typical readers showed an N400 effect characterized by significantly larger N400 amplitude elicited by nonwords than that elicited by real words. Children with reading difficulties showed similar N400 amplitudes for both nonwords and real words. Repeated measure ANOVA showed that word difficulty level modulated N400 amplitudes for typical readers but not for children with reading difficulties; typical readers showed larger N400 amplitudes when they read difficult nonwords compared to easier nonwords. Additionally, the N400 effect was significantly associated with sight word reading efficiency. Results were interpreted through the Reading System Framework. Orthographic-phonological regularity knowledge modulates meaning processing in typical readers; however, in children with reading difficulties, regularity knowledge may be less strong or less connected with meaning processing. Similarly, sub-lexical processes may be more proficient in typical readers.