Preattentive detection of auditory memory representations in accumulative drinker
Background: Chinese and English listeners did not show the same left-hemisphere (LH) lateralization as Thai listeners when making perceptual judgments of Thai tones. Although the left hemisphere is selectively employed for processing linguistic information irrespectively of acoustic cues or subtype of phonological unit, the right-hemisphere (RH) is employed for prosody-specific cues. Aims and Objective: As both hemispheres are lateralized for speech and language, the objective of this study is to extend the investigation of how the pre-attentive processing of contour tone changes of Thai monosyllabic words in alcoholic drinkers. Materials and Methods: Forty healthy right-handed adults participated in this study. Results: This study found that both rising-to-falling and falling-to-rising tone changes perception elicited Mismatch Negativity (MMN) between 217-264 msec with reference to the standard-stimulus Event-Related Potentials (ERPs). The rising-to-falling and falling-to-rising tone changes elicited a strong MMN for both groups. Source localization was obtained in the Middle Temporal Gyrus (MTG) of the right hemisphere (RH) for both groups. Conclusion: Automatic detection of changes in contour tones is a useful index of language universal auditory memory traces.