Influencing the N400: A study on factors that affect the N400 ERP component during sentence comprehension

Abstract

Effects of sentence position, word position, length, frequency, surprisal, LSA, concreteness, valence and arousal of nouns on the amplitude of the N400 ERP component were assessed during word-by-word rapid serial visual presentation of 205 sentences in 24 subjects. Linear mixed effects regression analyses revealed significant main effects for word position, length, surprisal, LSA, concreteness and valence. Interactions between length and frequency and between word position and surprisal revealed to have significantly influence on the size of the amplitude of the N400 component. The main effect of valence showed that nouns characterized as unhappy evokes smaller N400 amplitudes than nouns that are characterized as happy. The main effect of concreteness demonstrated that nouns with an increased concreteness produce bigger N400s than abstract words. The main effect of LSA showed that nouns that have a strong semantic relation with the preceding context evokes a drop in the amplitude of the N400. This last finding lead to the thought that word recognition takes place in a relatively late stage of the language processing stream.