N400 is a negative component occurring approximately 400 to 600 msec after a stimulus. It is most typically recorded during the presentation of a sequence of contextually related words in which one of the words is semantically incongruent. For example, the sentence “I take my coffee with cream and socks” would elicit a large N400 to the word “socks,” whereas the sentence “I take my coffee with cream and sugar” would not elicit an N400 to the word “sugar.” The more incongruous the word, the larger the N400 (for review, see Kutas and Van Petten 1988).
