N400 (neuroscience)

The N400 is a component of the event-related potential (ERP) that is observed in electroencephalography (EEG) studies. It is typically associated with language processing and is characterized by a negative voltage peak that occurs approximately 400 milliseconds after the presentation of a stimulus, particularly in response to semantic violations or unexpected words in a sentence. For example, if a sentence ends with a word that does not fit semantically with the preceding context (e.g.