The N400 component in children with reading difficulties

The N400 component in children with reading difficulties

First Author: Huilin Sun -- Texas A&M University
Additional authors/chairs: 
Steven Woltering
Keywords: EEG, N400, Literacy development, Dyslexia
Abstract / Summary: 

Purpose
This poster summarizes the research methods and findings on the N400 Event-Related Potential (ERP) component in children with reading difficulties. The N400 component is a characteristic waveform shown in electroencephalograms when individuals complete meaning-related tasks. It has not been widely studied in children, but correlations with reading were shown in adults. It may be a biomarker of reading-related processes. We aim to identify questions and gaps in the child N400 literature.

Method
A scoping literature review was conducted. A broad scope accommodates the limited body of research with varied participant characteristics and task design. Studies were included if their titles or abstracts contain “N400” and have participants under 18.

Results
N400 was elicited by a variety of tasks (picture, word, sentence). Researchers compared the characteristics (e.g., amplitudes) of N400 between conditions (e.g., pseudowords vs real words) and between age or reading groups. Correlations between language-literacy and N400 are often small.
Findings will be presented in a tabular format, including participant groupings, N400 tasks (stimulus, instruction, equipment, conditions), N400 characteristics (amplitudes, topography, experimental condition-level differences), standardized tasks (e.g., receptive vocabulary), N400-test score correlations, definitions of "reading difficulties", and theoretical frameworks.

Conclusion
Mixed findings exist regarding the N400 characteristics of children with reading difficulties. The relationship between language-literacy skills and N400 appears open for interpretations. E.g., while some found struggling readers to have larger N400 amplitudes indicative of strenuous processing, others found them to have smaller or no N400 indicative of a lack of meaning-processing due to decoding constraints. The next step may be developing N400 tasks and incorporating standardized tests based on strong theoretical frameworks.