Neural oscillatory evidence of the difference between emotional and conceptual processing in language comprehension

Despite ample study of conceptual and emotional information processing in language, it remains unclear whether these two types of processing rely on different neural mechanisms. In the present study, the processing of semantic and emotional information was directly compared in 24 participants undergoing electroencephalograms (EEGs). Participants read 120 scenarios ending in three ways (affectively and semantically congruent, affectively incongruent, and semantically incongruent) and were asked to judge the appropriateness of the last word within the context. The data were analyzed using both event-related potentials (ERPs) and event-related spectral perturbation (ERSP) analysis. In addition to the similar N400 effects evoked by both emotional and conceptual incongruity, conceptual incongruity elicited a larger theta power increase, while emotional incongruity induced a gamma band power increase, compared with the congruent condition. The different oscillatory patterns suggest that emotional and conceptual information in language processing may rely on different neural mechanisms, even though both types of processing produced a similar N400 effect.