The mismatch negativity as an index of temporal processing in audition

Objectives: The relation of the mismatch negativity (MMN) elicitation with behavioral stimulus discrimination as well as the replicability of the MMN was evaluated for intervals between paired tones. Methods: The MMN, obtained in a passive oddball paradigm in two sessions se parated by 4-21 days and behavioral responses (button presses to target sti muli) in a separate session were recorded from 10 adult healthy subjects. T he standard stimulus (P = 0.79) was a tone pair separated by a 120 ms silen t inter-stimulus interval (ISI) and the deviant stimuli were tone pairs wit h an ISI of 100, 60, and 20 ms (P = 0.07 for each). Results: The 20 and 60 ms ISI deviant tone pairs elicited a significant MMN during both recording sessions and they were also behaviorally discriminat ed, whereas neither did the 100 ins ISI deviant pair elicit significant MMN nor was it behaviorally discriminated. Furthermore, there was a significan t correlation between the MMN and reaction times to the 20 and 60 ins ISI d eviant pairs. The 20 ins ISI deviant stimulus elicited highly replicable MM Ns (r = 0.75), whereas the less well discriminated 60 ms ISI deviant pair d id not (r = 0.60). Conclusions: The MMN reflects discrimination accuracy of temporal sound int ervals, Furthermore, when the physical difference between the standard and deviant tone pair in the temporal domain is large, it is elicited with high reliability. (C) 2001 Elsevier Science Ireland Ltd. Alt rights reserved.