Indeed, many laboratories demonstrated that semantic anomalies were neither necessary nor sufficient for N400 elicitation and that N400s did not always pattern with RTs. Fischler and colleagues (1983), for example, found that N400 amplitudes to the final words in affirmative (e.g., A robin is a bird/vehicle) and negative (A robin is not a bird/vehicle) sentences were determined exclusively by the relationship between the first and the second noun, and not by sentence meaning or truth value (which did, however, affect verification times). Numerous other studies further demonstrated that N400 elicitation did not require a sentential frame; for example, N400 effects obtained when the fifth item of a list mismatched rather than matched the prior four in semantic category membership. N400 effects also were observed in lexical priming paradigms, where a target word was or was not somehow related (e.g., identically, associatively, semantically, categorically, and perhaps phonologically) to an immediately preceding (prime) word; in all cases, related items showed reduced N400 amplitudes relative to unrelated items across a number of different tasks (reviewed in Kutas & Van Petten 1988).
