Auditory cortex responds in 100 ms to incongruity of melody

In order to find the cortical neural activities that reflect musical processing, we conducted measurements of MEG responses while subjects listened to familiar melodies. Significant enlargement of the N1m peak was observed in the response to the endnote of a phrase that was deviated to out-of-key from the keynote. Equivalent current sources of the enlarged N1m response were localized in the cortical area of the superior temporal plane. These results suggest the possibility of fast neural processing, as early as 100 ms, of the auditory cortex detecting incongruity of a melody.