Event-related potentials elicited by wrong terminal notes: effects of temporal disruption.

Wrong terminal notes of familiar musical phrases are known to elicit a large positive deflection of the event-related potential (ERP). The present study examined whether the effect of wrong terminal notes on ERP was modulated by the timing of their occurrence. Sixteen non-musicians were asked to rate the congruity of the endings of 50 well-known musical phrases. Four different types of endings were made for each phrase by manipulating the timing (well-timed vs. delayed for 750 ms) and pitch (correct vs. wrong) of the last note orthogonally. These ending patterns were presented equiprobably in an unpredictable order. Wrong notes elicited large late positive waves irrespective of the timing of occurrence. When the notes were delayed, however, the positive waves were reduced in amplitude to about 50% of those elicited by well-timed notes. These results suggest that the temporal (rhythmic) structure of musical phrases strongly influences the processing of melodic information.