Preattentive Processing of Different Vowel Duration Changes with Level Tones in Monosyllabic Thai Words

摘要

The main objective of this study is to use the Mismatch Negativity (MMN) to provide an index of experience-dependent and long-term memory traces for duration of vowel changes with level tone in monosyllabic Thai words. About twenty two healthy right-handed adults participated in this study. It was found that both long to short and short to long duration of vowels changes with level tone elicited MMN between 184-208 msec with reference to the standard-stimulus ERPs. The long to short duration changes with level tone elicited a strong MMN bilaterally for both native and nonnative speaker of Thai unlike short to long duration change with level tone. The source of long to short duration changes was estimated to be located in the middle temporal gyrus of each hemisphere for both groups.