Activation of the auditory pre-attentive change detection system by tone repetitions with fast stimulation rate.

The human automatic pre-attentive change detection system indexed by the mismatch negativity (MMN) component of the auditory event-related brain potential is known to be highly adaptive. The present study showed that even infrequent repetitions of tones can elicit MMN, independently of attention, when tones of varying frequency are rapidly presented in an isochronous rhythm. This demonstrates that frequency variation can be extracted as an invariant feature of the acoustic environment revealing the capacity for adaptation of the auditory pre-attentive change detection system. It is argued that this capacity is related to the temporal-window of integration.