Effects of task language and second-language proficiency on the neural correlates of phonemic fluency in native Japanese speakers
Effects of task language and second-language proficiency on the neural correlates of phonemic fluency in native Japanese speakers
复制标题
任务语言和第二语言熟练程度对日语母语者音素流利度神经相关性的影响
DOI：
10.1097/wnr.0000000000000852
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发表时间：
2017
期刊：
影响因子：
1.7
通讯作者：
Shinoda Koh
中科院分区：
文献类型：
--
作者：
Wroblewski Greggory J.;Matsuo Koji;Hirata Keiko;Matsubara Toshio;Harada Kenichiro;Watanabe Yoshifumi;Shinoda Koh
在音素流利性测试(即Fas测试)中收集的数据可能与语言有关，也可能因第二语言水平的不同而不同。Fas测试是评估认知缺陷的神经心理单元的标准组成部分。任务语言独特的正字法/语音系统，以及双语者固有的认知优势，都可能影响任务的神经关联。然而，目前大多数测试音素流利性的研究都没有对语言背景进行评估。在这里，我们使用52通道功能近红外光谱学对大学年龄的日本本土受试者进行测试，以检测在用日语和英语进行音素流利任务时，氧合血红蛋白的功能变化。我们发现了与任务语言和第二语言水平相关的活动差异。除了在日语测试中激活的基因座外，在英语测试中还专门招募了双侧中央前通道。此外，熟练程度较高的组在两种语言背景下的氧合血红蛋白几乎没有增加，而熟练程度较低的参与者在两种背景下都表现出普遍的增加。我们将中央前活动的增加解释为在第二语言环境下额外招募发音资源的结果。至于高水平组没有这种差异，这可能反映了这一组在非语言执行控制方面的优势。综上所述，我们的结果表明，语言背景和语言熟练程度是语音流利性神经成像研究中的混杂变量，这种测量在不同语言背景的人群中的充分性需要在未来的研究中得到考虑。
Data collected during a phonemic fluency task (or ‘FAS test’), a standard component of neuropsychological batteries for assessment of cognitive deficits, may be language-dependent and may differ depending on second-language proficiency. The unique orthographic/phonological system of the task language, and the reported cognitive advantages inherent to bilinguals, may each influence the task’s neural correlates. However, language background is not currently assessed in most studies testing phonemic fluency. Here, we used 52-channel functional near-infrared spectroscopy in college-aged native-Japanese subjects to examine functional changes in oxygenated hemoglobin elicited during a phonemic fluency task performed in Japanese and in English. We found activity differences that were related to task language and second-language proficiency. Besides loci activated in the Japanese test, bilateral precentral channels were specifically recruited in the English test. Furthermore, the higher-proficiency group showed almost no increase in oxygenated hemoglobin in either language context, whereas participants with lower proficiency showed widespread increases for both contexts. We interpret precentral increases as the consequence of additional articulatory resource recruitment in a second-language context. As for the lack of such variation in the higher-proficiency group, it may reflect an advantage in nonverbal executive control in this group. Together, our results point to language background and proficiency as confounding variables in neuroimaging studies of phonemic fluency and that the adequacy of such measures in populations with varying language backgrounds needs to be considered in future studies.