RESEARCH ARTICLE


Left Inferior Frontal Activations Differentially Modulated by Scrambling in Ditransitive Sentences



Masatoshi Koizumi1, Jungho Kim1, Naoki Kimura1, Satoru Yokoyama2, Shigeru Sato3, Kaoru Horie4, Ryuta Kawashima2
1 Graduate School of Arts and Letters, Tohoku University, Sendai, Japan
2 Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
3 Sendai University, Shibata, Japan
4 Graduate School of Languages and Cultures, Nagoya University, Nagoya, Japan


© 2012 Koizumi et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Graduate School of Arts and Letters, Tohoku University, 27-1 Kawauchi, Aoba-ku, Sendai, 980-8576, Japan; Tel: +81-22-795-5981; Fax: +81-22-795-5981; E-mail: koizumi@sal.tohoku.ac.jp


Abstract

In order to clarify the relationship among grammatical knowledge, processing components, and neural substrates in sentence comprehension, we used functional magnetic resonance imaging to investigate how brain activation is affected by two types of scrambling (short scrambling and middle scrambling) in ditransitive sentences in Japanese. Short scrambling and middle scrambling enhanced activation in the anterior and posterior left inferior frontal gyrus respectively. This finding accords with the view that the anterior left inferior frontal gyrus is involved in the automatic processing that establishes a dependency relation between a verb and its arguments, and the posterior left inferior frontal gyrus supports this kind of processing through its role in verbal working memory. This result is more congruent with a process-based approach to neural bases for sentence processing, which searches for neurological correlates of psycholinguistically defined processing components, than with a grammar-based approach, which probes neural networks with the assumption that major grammatical operations are neurologically individuated.

Keywords: Functional magnetic resonance imaging, Japanese, scrambling, sentence processing, syntax, verbal working memory.