Specific Neural Traces for Intonational Discourse Categories as Revealed by Human-evoked Potentials

摘要

The neural representation of segmental and tonal phonologicalndistinctions has been shown by means of the MMN ERP, yet thisnis not the case for intonational discourse contrasts. In Catalan, anrising–falling intonational sequence can be perceived as a statementnor as a counterexpectational question, depending exclusivelynon the size of the pitch range interval of the risingmovement. Wentested here, using theMMN, whether such categorical distinctionsnelicited distinct neurophysiological patterns of activity, supportingntheir specific neural representation. From a behavioral identificationnexperiment, we set the boundary between the two categoriesnand defined four stimuli across the continuum. Althoughnthe physical distance between each pair of stimuli was kept constant,nthe central pair represented an across-category contrast,nwhereas the other pairs represented within-category contrasts.nThese four auditory stimuli were contrasted by pairs in three differentnoddball blocks. Themean amplitude of the MMN was largernfor the across-category contrast, suggesting that intonational contrastsnin the target language can be encoded automatically in thenauditory cortex. These results are in line with recent findings innother fields of linguistics, showing that, when a boundary betweenncategories is crossed, the MMN response is not just larger butnrather includes a separate subcomponent