Kutas’ mentor Donchin (1984) emphasized the importance of carefully characterizing ERP responses in terms of their functional sensitivity as a prerequisite to using them as markers of specific aspects of information processing. Accordingly, early years of work (reviewed in Hillyard & Kutas 1983; Kutas & Van Petten 1988) focused on determining what range of manipulations the N400 was and was not sensitive to (and how), and its relation to behavioral measures and other known ERP responses. Using the anomalous sentence paradigm as a starting point, the field asked whether N400 effects would obtain for any unexpected manipulation using words. The answer was a resounding no: there was no observable N400 effect to the final word of “I shaved off my mustache and BEARD” (a congruent but physically unexpected ending) compared to the physically expected congruent ending (beard). Likewise, the N400 also did not obtain in response to just any language-related violation: there were no N400 effects to simple grammatical (morphosyntactic) violations as in “All turtles have four leg” (versus legs). Other studies confirmed that the ERPs to all sentence final
