The influence of tone inventory on ERP without focal attention: a cross-language study.

This study investigates the effect of tone inventories on brain activities underlying pitch without focal attention. We find that the electrophysiological responses to across-category stimuli are larger than those to within-category stimuli when the pitch contours are superimposed on nonspeech stimuli; however, there is no electrophysiological response difference associated with category status in speech stimuli. Moreover, this category effect in nonspeech stimuli is stronger for Cantonese speakers. Results of previous and present studies lead us to conclude that brain activities to the same native lexical tone contrasts are modulated by speakers' language experiences not only in active phonological processing but also in automatic feature detection without focal attention. In contrast to the condition with focal attention, where phonological processing is stronger for speech stimuli, the feature detection (pitch contours in this study) without focal attention as shaped by language background is superior in relatively regular stimuli, that is, the nonspeech stimuli. The results suggest that Cantonese listeners outperform Mandarin listeners in automatic detection of pitch features because of the denser Cantonese tone system.

The effect of intertalker variations on acoustic-perceptual mapping in Cantonese and Mandarin tone systems.

PURPOSE: This study investigates the impact of intertalker variations on the process of mapping acoustic variations on tone categories in two different tone languages. METHOD: Pitch stimuli manipulated from four voice ranges were presented in isolation through a blocked-talker design. Listeners were instructed to identify the stimuli that they heard as lexical tones in their native language. RESULTS: Tone identification of Mandarin listeners exhibited relatively stable normalization regardless of the voice, whereas tone identification of Cantonese listeners was unstable and susceptible to the influence of intertalker variations. In the case of Cantonese listeners, intertalker variations had a larger effect on the perception of F0 height dimension than of F0 slope dimension. CONCLUSION: The comparison between Cantonese and Mandarin listeners' performances reveals an interaction of intertalker variations and the types of tone contrasts in each language. For Cantonese tones, which depend heavily on F0 height distinctions, intertalker variations result in F0 overlapping and, consequently, ambiguities among them in isolated tone perception. For Mandarin tones, which are distinctive in terms of their F0 contours, the differences in F0 contours alone seem sufficient to elicit reliable tone identification. Intertalker variations therefore have relatively limited effect on Mandarin tone perception.

[Clinical application studies on AFP-L3 detected by micro-spin column method].

OBJECTIVE: To explore the clinical value of Lens culinaris agglutinin-reactive alpha-fetoprotein in the differentiation diagnosis between benign and malignant liver diseases, as well as the early warning of hepatocellular carcinoma. METHODS: Alpha-fetoprotein variants from 300 patients with liver diseases were isolated with micro-spin column equipped lens culinaris agglutinin (LCA). The AFP and AFP-L3 were detected by the electrochemical luminescence (ECL) method, and the proportions of AFP-L3 were calculated. RESULTS: The positive rates of AFP-L3 of HCC patients and chronic liver disease patients were 95% and 64% respectively, there were significant difference in two groups (chi2 = 134.72, P < 0.01), the HCC incidence rates of AFP-L3 positive and negative chronic liver disease patients showed significant difference (chi2 = 80.158, P < 0.01). there were no correlations between the proportion of AFP-L3 and AFP consistency(r = 0.046, P > 0.05). CONCLUSIONS: The detection of AFP-L3 by micro-spin column assay show great clinical value in the differentiation diagnosis of benign and malignant liver diseases, as well as the early warning of hepatocellular carcinoma.