摘要：The mismatch negativity (MMN) has been used extensively to examine the sensitivity ofindividuals to speech sound contrasts. Nevertheless, it is relatively rare to find reports contrastingsounds with each sound serving as deviant in one condition and standard in another in a passiveoddball paradigm. A few studies that have done so have obtained asymmetry in MMN amplitude andin some cases latency for some pairs of sounds but not others (German vowels: Eulitz & Lahiri,2004; Japanese vowels: Ikeda et al., 2002; Hindi consonants: Shafer et al., 2004). Eulitz and Lahiri(2004) explained MMN asymmetry in terms of presence or absence of conflicting phonologicalfeatures between the surface form representing the deviant stimulus and the underlying form withunderspecified feature accessed by the standard stimulus. This study employed a passive oddballparadigm to examine whether asymmetric MMN occurred in two tonal contrasts, T1 [+Upperregister, h(igh) tone] vs. T6 [-Upper, l(ow)] and T4 [-Upper, hi] vs. T6, with T6 serving as deviantand standard stimuli in different blocks.
