Shinozuka Katsumasa, Niioka Kiyomitsu, Tokuda Tatsuya, Kyutoku Yasushi, Okuno Koki, Takahashi Tomoki, Dan Ippeita
Research and Development Initiatives, Applied Cognitive Neuroscience Laboratory, Chuo University, Tokyo, Japan.
Front Hum Neurosci. 2021 Feb 26;15:593108. doi: 10.3389/fnhum.2021.593108. eCollection 2021.
In the midst of globalization, English is regarded as an international language, or Lingua Franca, but learning it as a second language (L2) remains still difficult to speakers of other languages. This is true especially for the speakers of languages distantly related to English such as Japanese. In this sense, exploring neural basis for translation between the first language (L1) and L2 is of great interest. There have been relatively many previous researches revealing brain activation patterns during translations between L1 and English as L2. These studies, which focused on language translation with close or moderate linguistic distance (LD), have suggested that the Broca area (BA 44/45) and the dorsolateral prefrontal cortex (DLPFC; BA 46) may play an important role on translation. However, the neural mechanism of language translation between Japanese and English, having large LD, has not been clarified. Thus, we used functional near infrared spectroscopy (fNIRS) to investigate the brain activation patterns during word translation between Japanese and English. We also assessed the effects of translation directions and word familiarity. All participants' first language was Japanese and they were learning English. Their English proficiency was advanced or elementary. We selected English and Japanese words as stimuli based on the familiarity for Japanese people. Our results showed that the brain activation patterns during word translation largely differed depending on their English proficiency. The advanced group elicited greater activation on the left prefrontal cortex around the Broca's area while translating words with low familiarity, but no activation was observed while translating words with high familiarity. On the other hand, the elementary group evoked greater activation on the left temporal area including the superior temporal gyrus (STG) irrespective of the word familiarity. These results suggested that different cognitive process could be involved in word translation corresponding to English proficiency in Japanese learners of English. These difference on the brain activation patterns between the advanced and elementary group may reflect the difference on the cognitive loads depending on the levels of automatization in one's language processing.
在全球化进程中，英语被视为一种国际语言，即通用语，但对于其他语言的使用者来说，将其作为第二语言（L2）来学习仍然困难重重。对于那些与英语亲缘关系较远的语言的使用者，比如日语使用者，情况尤其如此。从这个意义上说，探索第一语言（L1）和L2之间翻译的神经基础具有极大的研究价值。此前已有相对较多的研究揭示了L1与作为L2的英语之间翻译过程中的大脑激活模式。这些聚焦于语言距离较近或适中的语言翻译研究表明，布洛卡区（BA 44/45）和背外侧前额叶皮层（DLPFC；BA 46）可能在翻译过程中发挥重要作用。然而，日语和英语之间语言距离较大的语言翻译的神经机制尚未明确。因此，我们使用功能性近红外光谱技术（fNIRS）来研究日语和英语单词翻译过程中的大脑激活模式。我们还评估了翻译方向和单词熟悉度的影响。所有参与者的第一语言都是日语，且他们正在学习英语。他们的英语水平为高级或初级。我们根据日本人对单词的熟悉程度选择英语和日语单词作为刺激材料。我们的结果表明，单词翻译过程中的大脑激活模式在很大程度上因他们的英语水平而异。高级组在翻译熟悉度较低的单词时，左侧前额叶皮层靠近布洛卡区的区域激活更强，但在翻译熟悉度较高的单词时未观察到激活。另一方面，初级组无论单词熟悉度如何，在包括颞上回（STG）在内的左侧颞区都有更强的激活。这些结果表明，在以日语为母语的英语学习者中，与英语水平相对应的单词翻译可能涉及不同的认知过程。高级组和初级组在大脑激活模式上的这些差异可能反映了根据语言处理自动化程度不同而产生的认知负荷差异。
