The Neural Correlates of Semantic and Grammatical Encoding During Sentence Production in a Second Language: Evidence From an fMRI Study Using Structural Priming

Eri Nakagawa; Takahiko Koike; Motofumi Sumiya; Koji Shimada; Kai Makita; Haruyo Yoshida; Hirokazu Yokokawa; Norihiro Sadato

doi:10.3389/fnhum.2021.753245

The Neural Correlates of Semantic and Grammatical Encoding During Sentence Production in a Second Language: Evidence From an fMRI Study Using Structural Priming

Front Hum Neurosci. 2022 Jan 17:15:753245. doi: 10.3389/fnhum.2021.753245. eCollection 2021.

Authors

Eri Nakagawa¹, Takahiko Koike¹, Motofumi Sumiya^{1

2

3}, Koji Shimada⁴, Kai Makita⁴, Haruyo Yoshida⁵, Hirokazu Yokokawa⁶, Norihiro Sadato^{1

7

8}

Affiliations

¹ Department of System Neuroscience, National Institute for Physiological Sciences (NIPS), Okazaki, Japan.
² Department of Cognitive and Psychological Sciences, Graduate School of Informatics, Nagoya University, Nagoya, Japan.
³ Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.
⁴ Research Center for Child Mental Development, University of Fukui, Fukui, Japan.
⁵ Department of English Education, Osaka Kyoiku University, Osaka, Japan.
⁶ School of Languages and Communication, Kobe University, Hyogo, Japan.
⁷ Department of Physiological Sciences, School of Life Sciences, The Graduate University for Advanced Studies (SOKENDAI), Kanagawa, Japan.
⁸ Biomedical Imaging Research Center (BIRC), University of Fukui, Fukui, Japan.

Abstract

Japanese English learners have difficulty speaking Double Object (DO; give B A) than Prepositional Object (PO; give A to B) structures which neural underpinning is unknown. In speaking, syntactic and phonological processing follow semantic encoding, conversion of non-verbal mental representation into a structure suitable for expression. To test whether DO difficulty lies in linguistic or prelinguistic process, we conducted functional magnetic resonance imaging. Thirty participants described cartoons using DO or PO, or simply named them. Greater reaction times and error rates indicated DO difficulty. DO compared with PO showed parieto-frontal activation including left inferior frontal gyrus, reflecting linguistic process. Psychological priming in PO produced immediately after DO and vice versa compared to after control, indicated shared process between PO and DO. Cross-structural neural repetition suppression was observed in occipito-parietal regions, overlapping the linguistic system in pre-SMA. Thus DO and PO share prelinguistic process, whereas linguistic process imposes overload in DO.

Keywords: L2 sentence production; fMRI; priming; repetition suppression; speaking.