Mismatch Negativity (MMN) evoked by sound duration contrasts: An unexpected major effect of deviance direction on amplitudes

Differential waveforms referred to the tip of the nose and grand averaged across all subjects at all recording sites. The white, black and grey bars, respectively, represent temporal time course of the standard (this figure: 100ms), short and long deviant tones. The waveforms evoked by short deviants are plotted in black, those evoked by long deviants are in grey.

Differential waveforms evoked by the short and long deviants against the 150ms standard condition at all recording sites. Legend: see Fig. 1.

Differential waveforms evoked by the short and long deviants against the 200ms standard condition at all recording sites. Legend: see Fig. 1.

Differential waveforms evoked by the short and long deviants against the 250ms standard condition at all recording sites. Legend: see Fig. 1.

Differential re-referenced waveforms evoked by the short and long deviants against the four standard duration conditions. The grey and black bars, respectively, represent standard and deviant sounds. Within each vignette, the lower tracings illustrate the results of t-tests carried out during the 300 ms time window. The level is raised during each period of consecutive significant t-tests.

Bar graphs illustrating the mean and standard deviations of the MMN latencies and absolute amplitudes across all conditions for which an MMN was obtained. Black bars represent short deviants and grey bars long deviants.

Reaction times (mean and standard deviations) for short (black circles) and long (grey circles) across standard durations showing the interaction between standard duration and deviance direction. Black asterisks indicate significant post hoc tests for the short vs long deviant comparisons and grey asterisks indicate significant post hoc tests for the standard duration comparisons within long deviants.