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.