An fMRI investigation of speech and tone segmentation
An fMRI investigation of speech and tone segmentation
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DOI：
10.1162/0898929042568433
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发表时间：
2004-11-01
影响因子：
3.2
通讯作者：
Burton, MW
中科院分区：
文献类型：
--
作者：
LoCasto, PC;Krebs-Noble, D;Burton, MW
最近的研究强烈表明，语音任务激活额下回的一个亚区。本fMRI研究的目的是调查在语音加工过程中激活该区域的程度是由于语音过程本身，如发音编码或其他认知任务的要求，如工作记忆。因此，我们比较了激活模式的语音和音调序列的语音识别任务的分割。特别是，参与者对需要分割连续声学信号的成对单词、伪词和音调序列以及不需要分割的音调对进行相同/不同的判断。准确性和反应时间的数据表明，语音和音调序列分割条件模式更类似于对方比音调歧视对。组数据的分析显示，强激活的区域在边界的左额下回和中额回的所有三个分割条件相比，音调的歧视，但没有一致的差异时，观察到字和伪词分割直接对比。对个体受试者的分析表明，与序列相比，大量参与者在语音条件下激活了额中回的一个小区域。这些结果表明，一个显着的一部分活跃的额叶区被招募提取声学信息，并保持在记忆中的决定。然而，在额下回/额中回的边界处的一些区域可能是语音分割所独有的。
Recent research strongly indicates that phonological tasks activate a subregion of the inferior frontal gyrus. The purpose of the present fMRI study was to investigate the extent to which activation of this region during phonological processing is due to speech processes per se such as articulatory recoding or to other cognitive task demands such as working memory. Thus, we compared activation patterns during segmentation of speech and tone sequences to a tone discrimination task. In particular, participants performed same/different judgments on pairs of words, pseudowords, and tone sequences that required segmentation of a continuous acoustic signal as well as tone pairs that did not require segmentation. Accuracy and reaction time data showed that speech and tone sequence segmentation conditions patterned more similarly to each other than to tone discrimination pairs. Analyses of group data revealed strong activation of the region at the border of the left inferior and middle frontal gyrus for all three segmentation conditions compared to tone discrimination, but no consistent differences were observed when word and pseudoword segmentation were directly contrasted. Analyses of individual subjects indicated that a large number of participants activated a small area of the middle frontal gyrus during the speech conditions compared to the sequences. These results suggest that a significant portion of active frontal areas is recruited for extracting acoustic information and maintaining it in memory for decision. However, some regions at the border of the inferior/middle frontal gyrus may be unique to speech segmentation.