The N400 is an event related potential that is elicited through semantically incongruent stimuli and measured using EEG. By way of analysing the relation of interaction and narrative in modern interactive media (video games) the theory of narrative coherence is put forth as a solicitor of flow zones, achievable through balance of challenge and ability, through 4 different scenarios encompassing authorial intent in regard to narrative & interaction and the subjective emergence spawned thereof. By viewing interaction as an intrinsic part of video game narrative, previous N400 research reveals that the ERP has been demonstrated using semantically incongruent text, pictures, audio and film. A test is designed to demonstrate N400 with an interactive control within a detailed virtual environment in the form of DADIU game Cantrip. 30 participants take part in the test involving 8 scalp electrodes being worn while playing Cantrip. 15 trigger points with 4 states of measurement each are placed within the game in order to assess participant reaction to incongruent stimulus onset (control scheme change). Robust N400 ERPs are found in one of the averaged states of the test group.