Effect of syntactic similarity on cortical activation during second language processing: A comparison of English and Japanese among native Korean trilinguals

Abstract

In this study of native Korean trilinguals we examined the effect of syntactic similarity between first (L1) and second (L2) languages on cortical activation during the processing of Japanese and English, which are, respectively, very similar to and different from Korean. Subjects had equivalent proficiency in Japanese and English. They performed auditory sentence comprehension tasks in Korean, Japanese, and English during functional MRI (fMRI). The bilateral superior temporal cortex was activated during the comprehension of three languages. The pars triangularis of the left inferior frontal gyrus (IFG) was additionally activated for L2 processing. Furthermore, the right cerebellum, the pars opercularis of the left IFG, and the posteriomedial part of the superior frontal gyrus were activated during the English tasks only. We observed significantly greater activation in the pars opercularis of the left IFG, the right cerebellum, and the right superior temporal cortex during the English than Japanese task; activation in these regions did not differ significantly between Korean and Japanese. Differential activation of the pars opercularis of the left IFG and the right cerebellum likely reflects syntactic distance and differential activation in the right superior temporal cortex may reflect the prosodic distance between English from Korean and Japanese. Furthermore, in the pars oparcularis of the left IFG and the right cerebellum, significant negative correlation between the activation and duration of exposure was observed for English, but not for Japanese. Our research supports the notion that linguistic similarity between L1 and L2 affects the cortical processing of second language.

How age of acquisition influences brain architecture in bilinguals

“…To provide a more detailed analysis, we divided the IFG into three sub-regions [pars opercularis (IFGop), pars triangularis (IFGpt), and pars orbitalis (IFGor)], the posterior parietal cortex into three sub-regions [supramarginal gyrus (SMG), angular gyrus (AG), and superior parietal lobule (SPL)], leading to a total of 12 ROIs in the left hemisphere. The selection of the 12 ROIs are also consistent with other previous studies (Hernandez & Li, 2007; Jeong et al, 2007; Mechelli et al, 2004). Functionally, it has been generally accepted that more extensive left hemisphere activations are associated with bilinguals than monolinguals especially in late bilinguals and low proficiency bilinguals.…”

L1 and L2 processing in the bilingual brain: A meta-analysis of neuroimaging studies

“…Note: Studies with multiple tasks were used more than once in data analysis (e.g., Buchweitz et al, 2012). b Participants' mean age was not reported in the following studies, where the minimal and maximal ages were averaged as the mean age (Chan et al, 2008;Chee et al, 2001;De Bleser and Kauschke, 2003;Golestani et al, 2006;Huang et al, 2012;Jeong, Sugiura, Sassa, Haji, et al, 2007;Luke et al, 2002;Nakamura et al, 2010;Perani et al, 1998Perani et al, , 2003Rao et al, 2013;Tan et al, 2003;Tham Wei Ping, 2003;Wang et al, 2010). …”

Language exposure induced neuroplasticity in the bilingual brain: A follow-up fMRI study

“…So far, many studies have investigated brain activities of bilinguals involved in the processing of L1 and L2, and as summarized by Indefrey (2006) and Abutalebi (2008), differences between L1 and L2 are usually reflected at the brain level by more extended activation patterns of L2 within or surrounding those regions responsible for L1 processing. As to why L2 engages more widespread brain activity, several studies have also suggested that the brain activity for language processing is modulated by specific demographic, linguistic and/or behavioral variables, such as language exposure in daily life Jeong et al, 2007;Perani et al, 2003), proficiency level (PL) (Briellmann et al, 2004;Chee, Caplan, et al, 1999;Frenck-Mestre, Anton, Roth, Vaid, & Viallet, 2005;Gandour et al, 2007;Golestani et al, 2006;Illes et al, 1999;Kotz, 2009;Perani et al, 1996Perani et al, , 1998, age-of-acquisition (AoA) of L2 (Bloch et al, 2009;Dehaene et al, 1997;Hernandez, Hofmann, & Kotz, 2007;Kim, Relkin, Lee, & Hirsch, 1997;Mayberry, Chen, Witcher, & Klein, 2011;Perani et al, 2003;Wartenburger et al, 2003), cross-linguistic similarities/dissimilarities (Jeong et al, 2007;Saur et al, 2009), and syntactic complexity (Suh et al, 2007;Yokoyama et al, 2006). Following Abutalebi and Green (2007), the extra-activity of L2 would be induced by an apparent lack of automaticity such as in cases where the proficiency for L2 is low or, likewise, when L2 is learnt later in life.…”

“…Language exposure was by then hypothesized to predict language outcome in bilingual aphasia, in the sense that the language the patient used more prior to the brain insult, was the one with the highest possibilities for recovery (see for discussion in . To the best of our knowledge, only very few functional neuroimaging studies have analyzed the effects of language exposure upon the cerebral representation of languages in bilinguals Jeong et al, 2007;Perani et al, 2003). For example, Perani et al (2003) carried out an fMRI study in high proficient Catalan-Spanish early bilinguals performing a lexical search and retrieval task, and found additional brain activity in the left middle frontal gyrus (MFG) (BAs 10, 46) and left inferior parietal lobule (IPL) (BA 40) only for the L2 to which subjects were less used.…”

“…The authors suggested that the activity found in the caudate nucleus and the ACC was specifically related to cognitive control mechanism and may reflect the switching cost when switching into a less exposed language. Jeong et al (2007) examined the brain activation of Korean trilinguals in auditory sentence comprehension tasks in Korean, Japanese, and English, and found the brain activation in the opercular portion of left inferior frontal gyrus (IFG) (BA 44) and in the right cerebellum were significantly negatively correlated with the length of stay in English-speaking country. The authors suggested that this effect might be caused by the linguistic distance between languages at the syntactical level.…”