N450 as a candidate neural marker for interference control deficits in children with learning disabilities

A deficit in the ability to suppress irrelevant or interfering stimuli may account for a variety of dysfunctional behaviors in children with learning disabilities (LD). However, neural correlates underlying this deficit in interference control in the LD are still unknown. In this study, we recruited a group of children with LD (age: 10.78 ± 0.52) along with an age-matched control group (age: 10.74 ± 0.86) and asked them to perform a numerical Stroop task. During the task, we used electroencephalogram (EEG) to record their event-related potentials (ERPs). We further evaluated performance of these children on a battery of tests, including the Academic Adaptability Test (AAT), an adapted Chinese version of Pupil Rating Scale (PRS), and Raven's Standard Progressive Matrices (SPM). Children's scores on recent math and Chinese exams were also obtained. Results showed that: 1) children with LD had worse performance in the incongruent condition of the numerical Stroop task suggesting that children with LD had interference control deficits but not basic numerical cognition; 2) children with LD had larger N450 effects on the frontal and posterior sites, but did not show any difference in early ERP components, suggesting that the behavioral difference was related with interference control rather than early visual perception processing; and 3) N450 effects were correlated with accuracy in the numerical Stroop task, performance in Raven's SPM, as well as school math performance. These results suggest that N450 can serve as a potential electrophysiology marker for identifying and potentially, providing targeted intervention for children with LD.