Dipartimento di Psicologia Generale, University of Padova, Padova, Italy.
Brain Res. 2010 Dec 17;1366:149-61. doi: 10.1016/j.brainres.2010.09.104. Epub 2010 Oct 30.
This study aimed at investigating the effects of acoustic distance and of speaker variability on the pre-attentive and attentive perception of French vowels by French adult speakers. The electroencephalogram (EEG) was recorded while participants watched a silent movie (Passive condition) and discriminated deviant vowels (Active condition). The auditory sequence included 4 French vowels, /u/ (standard) and /o/, /y/ and /ø/ as deviants, produced by 3 different speakers. As the vowel /o/ is closer to /u/ than the other deviants in acoustic distance, we predicted smaller mismatch negativity (MMN) and smaller N1 component, as well as higher error rate and longer reaction times. Results were in line with these predictions. Moreover, the MMN was elicited by all deviant vowels independently of speaker variability. By contrast, the Vowel by Speaker interaction was significant in the Active listening condition thereby showing that subtle within-category differences are processed at the attentive level. These results suggest that while vowels are categorized pre-attentively according to phonemic representations and independently of speaker variability, participants are sensitive to between-speaker differences when they focus attention on vowel processing.
本研究旨在探讨在法国成年母语者的前注意和注意阶段，声学距离和说话人变异性对法语元音感知的影响。研究中，参与者观看无声电影（被动条件）和辨别变异元音（主动条件），同时记录脑电图（EEG）。听觉序列包括 4 个法语元音，/u/（标准）和/o/、/y/和/ø/作为变异元音，由 3 个不同的说话人发出。由于在声学距离上，元音/o/比其他变异元音更接近/u/，因此我们预测其失匹配负波（MMN）和 N1 成分更小，错误率更高，反应时间更长。结果与这些预测一致。此外，所有变异元音都能引出 MMN，而与说话人变异性无关。相比之下，在主动聆听条件下，元音与说话人之间的交互作用显著，这表明在注意水平上可以处理细微的类别内差异。这些结果表明，虽然元音在前注意阶段根据音位表示进行分类，并且独立于说话人变异性，但当参与者将注意力集中在元音处理上时，他们对说话人之间的差异很敏感。
