Revisiting hemispheric lateralization for Cantonese lexical tone processing in dichotic listening

Abstract

In this study, we aim to re-examine the issue of hemispheric lateralization for Cantonese lexical tone processing in dichotic listening. We are particularly interested in testing whether the previously reported the right-hemisphere advantage in Cantonese lexical tone processing in dichotic listening [1] is replicable. More importantly, we aim to explore whether the brain lateralization pattern for tone processing is influenced by tone awareness. Sixteen native Cantonese speakers that were proficient in Jyutping and eighteen matched controls were asked to discriminate and identify Cantonese tones in dichotic listening. A right-hemisphere advantage was found in the discrimination task but not in the identification task. Findings from the discrimination task were generally consistent with [1] and supported the acoustic hypothesis of brain lateralization in lexical tone processing. However, the identification task might require more higher-level linguistic processing in the left hemisphere, resulting in more bilateral processing. No differences in hemispheric advantage were found between the two groups, although the Jyutping group outperformed controls in tone discrimination and identification in some conditions. The temporary conclusion is that late learning of Jyutping in adulthood may have limited effect on reshaping the brain lateralization of Cantonese lexical tone processing.