Rapid Semantic Processing: An MEG Study of Narrative Text Reading

Abstract

Research has shown that semantic analysis occurs at early stages of word processing (less than 200 ms). While traditional studies have focused on isolated words/sentences, our research explores rapid semantic processing during reading stories using event-related potentials and magnetoencephalography. We employed the rapid serial visual presentation paradigm to present texts word by word. Each word presentation lasted 150 ms, enhancing rapid semantic processing. We computed semantic dissimilarity (SD) values for each word and categorized them into quartiles to investigate their effect on brain responses. Our analysis revealed significant ERP differences within early time windows (120-132 ms). Two distinct clusters were identified: positive in the right occipital region and negative in the left temporal region. In both clusters less pronounced responses were registered for words with lowest SD which corresponds to theories of predictive coding. These findings broaden our understanding of rapid semantic processing and suggest new methodology.