Cortical activation in the processing of passive sentences in L1 and L2: an fMRI study.
The question of whether the bilingual brain processes a first and second language (L1 and L2, respectively) differently is a central issue in many psycholinguistic and neurolinguistic studies. This study used functional magnetic resonance imaging (fMRI) to investigate whether late bilinguals process structurally complex sentences in L1 and L2 in different cortical networks. For this purpose, we directly compared brain activity during the processing of active and passive sentences in both L1 and L2. We asked 36 healthy subjects to judge whether or not a presented sentence was semantically plausible. Both L1 and L2 activated the left hemispheric language-related regions such as the left inferior frontal, superior/middle temporal, and parietal cortices. However, we found different activation patterns between L1 and L2 in the processing of passive sentences. Passive sentences elicited greater activation than their active counterparts in the left pars triangularis, the premotor area, and the superior parietal lobule in Japanese, but not in English. Furthermore, there was a significant interaction between sentence type (active versus passive) and language (Japanese versus English) in the left pars orbitalis. The results of this study indicate that late bilinguals use similar cortical regions to comprehend both L1 and L2. However, when late bilinguals are presented with structurally complex sentences, the involvement of these regions differs between L1 and L2. These results suggest that, in addition to age of L2 acquisition and L2 proficiency, differences in grammatical construction affect cortical representation during the comprehension of L1 and L2.
Yokoyama
Satoru
S
Graduate School of International Cultural Studies (GSICS), Tohoku University, Kawauchi, Aoba-ku, Sendai-shi, Miyagi-ken, 980-8576, Japan. yokoyama@idac.tohoku.ac.jp
Okamoto
Hideyuki
H
Miyamoto
Tadao
T
Yoshimoto
Kei
K
Kim
Jungho
J
Iwata
Kazuki
K
Jeong
Hyeonjeong
H
Uchida
Shinya
S
Ikuta
Naho
N
Sassa
Yuko
Y
Nakamura
Wataru
W
Horie
Kaoru
K
Sato
Shigeru
S
Kawashima
Ryuta
R
D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D011578:Psycholinguistics; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D011932:Reading