The role of affective meaning, semantic associates, and orthographic neighbours in modulating the N400 in single words
The N400 has been seen to be larger for concrete than abstract words, and for pseudowords than real words. Using a word vector analysis to calculate semantic associates (SA), as well as ratings for emotional arousal (EA), and a measure of orthographic neighbourhood (ON), the present study investigated the relation between these factors and N400 amplitudes during a lexical decision task using Swedish word stimuli. Four noun categories differing in concreteness: specific (squirrel), general (animal) emotional (happiness) and abstract (tendency) were compared with pseudowords (danalod). Results showed that N400 amplitudes increased in the order emotional < abstract < general < specific < pseudoword. A regression analysis showed that the amplitude of the N400 decreased the more semantic associates a word had and the higher the rating for emotional arousal it had. The N400 also increased the more orthographic neighbours a word had. Results provide support for the hierarchical organisation of concrete words assumed in lexical semantics. They also demonstrate how affective information facilitates meaning processing.
Keywords: concreteness, emotional arousal, semantic associates, semantic specificity, N400, orthographic neighbours: ERP, lexical decision, word vector