Researchers from the Neurocognition of Language Lab at Teachers College, Columbia University, conducted a pretest-posttest intervention study over the 2018–2019 academic year. Using high-density electroencephalography (EEG) and a specific measure of word reading expertise, the N170 event-related brain potential, they investigated shifts in neural responses to specific stimuli (real words, nonwords, and strings of symbols). Students with and without reading disabilities in Grades 4–7 between the ages of 10 and 12 participated (n = 21). Students who qualified for intensive intervention enrolled in the System 44 program delivered in an afterschool setting at the Teachers College campus three days a week over the academic year. The study included three groups: 1) typically developing advanced decoders (TDA, n = 7); 2) typically developing decoders (TDD, n = 5); and 3) students with reading disabilities (SRD, n = 9).
Study findings revealed a left-lateralized N170 effect (a difference in hemisphere response associated with word reading expertise) for the TDA group only. For the TDD and SRD groups, responses to stimuli remained similar between the right and left hemispheres of the brain. A correlation analysis indicated that N170 adaptive mean amplitude measures for the word condition were strongly correlated with Phonics Inventory® scores and Orthographic Choice Task scores. These behavioral measures were also statistically significant predictors of the N170 adaptive mean amplitude value in the left hemisphere for the word condition. The lateralization of the N170 brain response was associated with phonological and orthographic knowledge beyond a basic threshold, across students. Study outcomes suggest a complementary interaction between orthographic knowledge and phonemic skills during the protracted development of the brain’s reading network.