Three-chord harmonic sequences with unexpected out-of-key endings: are they suitable stimuli for eliciting N400 responses?

A series of ERP components, each provided with both a precise timing with respect to stimulation and a specific cortical localization, reflects the temporal succession of processing stages of music information. We unexpectedly observed a N400-like component. This suggests that even chord-primed chord targets can convey extra-musical meanings and that, consequently, they might be useful in assessing residual higher-order information-processing capabilities in non-communicating patients with disorders of consciousness.