Effects of Orthographic-Semantic Consistency on Event-Related Potentials in Lexical Decision and Relatedness Judgment Tasks

Behavioral and ERP data reported in "Effects of Orthographic-Semantic Consistency on Event-Related Potentials in Lexical Decision and Relatedness Judgment Tasks" authored by Mitsuki Tachibana, Testuo Kida, Steve Lupker and Yasushi Hino. Orthographic-Semantic (O-S) consistency is a measure of the consistency with which specific orthographic forms are mapped onto specific meanings. Using Hino, Miyamura and Lupker’s (2011) norms in which O-S consistencies are computed based on orthographic neighbors, we varied O-S consistency for Japanese words (i.e., more O-S consistent words versus less O-S consistent words) and examined the impact of O-S consistency in lexical decision and relatedness judgment tasks. In both tasks, although we failed to detect an O-S consistency effect in the behavioral data, a significant effect was observed on the event-related brain potentials: the amplitudes of N400s were larger for the less O-S consistent words than for the more O-S consistent words, although the topographical distributions were somewhat different in the two tasks. The behavioral and ERP data in the lexical decision task (Experiment 1) and the relatedness judgment task (Experiment 2) are reported.