The individual replicability of mismatch negativity at short and long inter-stimulus intervals

Objectives: The individual replicability of the mismatch negativity (MMN) event-related brain potential (ERP) was studied at two different inter-stimulus intervals (ISIs), to establish its potential value for routine clinical evaluation of sound discrimination and auditory sensory memory. Methods: Ten healthy young subjects were presented sequences of 3 stimulus trains, in two recording sessions approximately 1 month apart. The stimuli in the trains were delivered at an ISI of 300 ms, whereas the inter-train intervals (ITIs) were 0.4 s and 4.0 s in different blocks. ERPs were averaged to standard (75 ms) and deviant (25 ms) tones started equiprobably the stimulus trains. Results: Significant Pearson product-moment correlations coefficients were found between sessions at all scalp locations fur the short ITI, when the MMN was quantified as the mean amplitude in the 100-200 ms latency window around its peak, However. none of the correlations reached significance for the longer ITI. Conclusions: MMN appears ro be a reliable measure for single-case assessment and follow-ups when obtained at short ISIs and quantified as an integrated window of neuroelectric activation over a temporal span. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.